Use of polyolefins having isotactic structural elements in flooring materials

ABSTRACT

The present invention relates to the use of polyolefins having isotactic structural elements in floor coverings, in particular in carpets or artificial lawns.

The present invention relates to the use of polyolefins having isotacticstructural elements in floor coverings, in particular in carpets orartificial lawns.

The use of amorphous olefin polymers for producing carpets and/or carpetnonwovens has been known for a long time. Thus, for example, U.S. Pat.No. 3,928,281 describes the use of a combination of atacticpolypropylene and urethane prepolymers and also inorganic fillermaterials for producing a carpet rear-side backing. The use ofisocyanate-containing compounds in carpet production is disadvantageouswith regard to the recycleability of such carpets and for toxicologicalreasons. In addition, the atactic polypropylene used does not have thematerials properties required for simultaneous nap and filament binding,e.g. a defined polymer structure. In particular, low application weightscannot be achieved.

The use of hot melt adhesives for producing carpet rear-side coatings isalready known from U.S. Pat. No. 3,551,231. The hot melt adhesives usedare produced, in particular, on the basis of poly(ethylene-co-vinylacetate) and pressed into the raw carpets by means of a particularpressing mechanism. However, the base polymers used do not have thematerials properties required for simultaneous nap and filament binding;in particular, low application weights cannot be achieved.

U.S. Pat. No. 3,982,051 describes the use of hot melt adhesives forcarpet rear-side coating. Here, the hot melt adhesives are produced onthe basis of ethylene copolymers having a high ethylene content, e.g.poly(ethylene-co-vinyl acetate), poly(ethylene-co-alkyl acrylate),atactic polypropylene and vulcanized rubber. The combination ofmaterials used does not have the materials properties required forsimultaneous nap and filament binding; in particular, low applicationweights cannot be achieved.

EP 0518014 describes three-dimensionally deformable recycleable floorcarpets, in particular automobile floor carpets, and also a process forproducing them, in which the rear-side coating of the carpet is carriedout using a moulding composition containing from 10 to 95% by weight ofone or more largely amorphous polyolefins. The largely amorphouspolyolefin used has a melt viscosity at 190° C. of from 2000 to 200000mPa*s and a softening point of from 70 to 160° C. and also a needlepenetration of from 5 to 50*0.1 mm. In particular, the production of acarpet rear-side coating using a high to very high filler content isdescribed. Simultaneous nap and/or filament binding is not described.The amorphous polyolefins mentioned are, owing to their sometimes veryhigh melt viscosity, unable to ensure sufficient penetration of the rawcarpet. In particular, the necessary combination of low melt viscosityat the application temperature and high tensile strength, flexibilityand adhesive shear strength in the cooled state is not ensured.

EP 0592683 describes a two-stage process for producing carpet nonwovensusing amorphous polyolefins, in which the polymer composition appliedhas a melt viscosity of from 2000 to 100000 centipoise and anapplication weight of from 200 to 2000 g/m² is used. The amorphousolefin polymers present in the polymer composition (5-95% by mass) arehomopolymers and/or copolymers of ethylene, propylene and/or 1-butenewhich are essentially amorphous and have no crystallinity. They have amelt viscosity of from 300 to 30000 centipoise and a softening point offrom 100 to 170° C. However, such amorphous polymers do not have goodmaterials properties and also do not make it possible to produce carpetswith a low application weight. In particular they do not make itpossible for a high adhesive shear strength on untreated polypropylene,a high tensile strength and a high elongation at break to be achieved atthe same time as a low melt viscosity. In addition, such amorphouspolyolefins generally have a high polydispersity and the low molecularweight constituents present in them are easily given off as gases.Furthermore, the production process described has considerable processengineering disadvantages which make the economics of the processquestionable as a result of its two-stage nature (separate nap/filamentbinding and carpet rear-side coating).

A process for nap and filament binding using hot melt adhesives based onamorphous poly(1-olefins) is also known from EP 1375731. However, theamorphous poly(1-olefin)s used there have a melt viscosity of from 2000to 200000 mPa*s at 190° C. and therefore largely a poor flowability, asa result of which it is difficult to produce strong composites at lowapplication weights. In addition, in the case of the amorphouspoly(1-olefins) indicated, a combination of low viscosity, high tensilestrength and good adhesive shear strength on untreated polypropylene isnot ensured, so that a comprehensive and complex formulation of theamorphous poly(1-olefins) is always necessary to achieve an industriallysatisfactory solution.

In general, polyolefins are frequently used for producing floorcoverings, in particular carpets. Thus, for example, WO 93/12285describes fully recycleable tuft carpets based on syntheticthermoplastic polymers, in which, in particular, all constituents of thetuft carpets belong to one polymer family. In addition to polyamides orpolyesters, the use of polypropylene is also explicitly described here.In particular, hot melt adhesives based on synthetic thermoplasticpolymers, which in the case of polypropylene carpets are formulated onthe basis of atactic polypropylene, are used. A combination of lowviscosity, high tensile strength and good adhesive shear strength onuntreated polypropylene is, however, not ensured when using atacticpolypropylene, so that a comprehensive and complex formulation is alwaysnecessary for an industrially satisfactory solution.

Furthermore, WO 98/38374, WO 98/38375 and US 2005/0266206, for example,describe the use of homogeneously branched polyethylene (e.g.poly(ethylene-co-1-octene)) having a high molecular weight for theproduction of carpet rear-side coatings. However, such polymers have,owing to their high melt viscosity at customary processing temperatures,a poor penetration behaviour in respect of the carpet backing materialand also, owing to their branches, generally underdeveloped flowproperties.

WO 2000/22226 describes the use of specific (1-olefin) copolymers forcarpet production. Comonomers used are, in particular, vinylaromatic orsterically hindered cycloaliphatic comonomers. In particular, thepolymers used are poly(ethylene-co-styrene). The polymers used have, inparticular, a high molar mass and are, according to the examples,processed at very high melt temperatures of >450° C. Thepoly(ethylene-co-styrene) polymers described are very complicated toprepare and process; in particular, the removal of styrene which has notbeen incorporated into the polymer presents problems whose solutionrequires a high technological outlay and makes the process economicallyuninteresting. The very high melt temperatures (which are necessary,inter alia, because of the high molar masses) are also prohibitive forthe processing of thermally sensitive raw carpets.

The use of metallocene compounds as catalyst in olefin polymerizationhas likewise been known for a long time. Kaminsky et al. have shown thatthe catalyst system cyclopentadienylzirconiumdichloride/methylaluminoxane (Cp₂ZrCl₂/MAO) is very suitable forpolymerization (Adv. Organomet. Chem. 1980, 18, 99-149). The MAO use,viz. methylaluminoxane (a partial hydrolysis product oftrimethylaluminium), functions as cocatalyst. Since this time, the useof metallocene compounds in conjunction with MAO in polymerizationreactions has become widespread. Thus, there are many publicationsconcerned with the metallocene-catalyzed polymerization of olefins, forexample of propene, e.g. U.S. Pat. No. 6,121,377, EP 584 609, EP 516018, WO 2000/037514, WO 2001/46274 and US 2004/0110910.

In the polymerization of propene or its higher homologs, formation ofdifferent relative stereoisomers can occur. The regularity with whichthe configurative repeating units follow one another in the main chainof a macromolecule is referred to as tacticity. To determine thetacticity, the monomer units of a polymer chain are examined and therelative configuration of each (pseudo)asymmetric chain atom relative tothe preceding one is determined. The term isotacticity is used when theobserved relative configuration of all (pseudo)asymmetric chain atoms isalways the same, i.e. the chain is made up of only one configurativerepeating unit. On the other hand, the term syndiotacticity is used whenthe relative configuration of successive (pseudo)asymmetric chain atomsis in each case the opposite. i.e. the chain is made up of two differentconfigurative repeating units which alternate.

Finally, in the case of atactic polymers, the different configurativerepeating units along the chain are arranged randomly.

The physical properties of propylene polymers are dependent first andforemost on the structure of the macromolecules and thus also on thecrystallinity, their molecular weight and the molecular weightdistribution and can be influenced by the polymerization process usedand, in particular, the polymerization catalyst used [R. Vieweg, A.Schley, A. Schwarz (editors); Kunststoff Handbuch; vol.IV/“Polyolefine”; C. Hanser Verlag, Munich 1969].

Polypropylene polymers are therefore classified according to theirtacticity into atactic, isotactic and syndiotactic polymers. Inaddition, there are the special forms of hemiisotactic polypropylenepolymers and stereoblock polymers. The latter are usually polymershaving isotactic and atactic stereoblocks and behave like thermoplasticelastomers since physical crosslinking of the polymer chains takes placeand leads to a joining of different crystalline polymer regions (A. F.Mason, G. W. Coates in: “Macromolecular Engineering”; Wiley-VCH,Weinheim; 2007).

Atactic polypropylene has a low softening point, a low density and goodsolubility in organic solvents. Classical atactic polypropylene (aPP)has a very broad molecular weight distribution which firstly leads to abroad melting range and secondly results in a high proportion of lowmolecular weight material which has a more or less strong tendency tomigrate. aPP has a very low tensile strength of about 1 MPa, but on theother hand has a very high elongation at break of up to 2000% (H.-G.Elias; Makromoleküle; vol. III; Wiley-VCH; Weinheim; 2001). Owing to thelow softening point, the heat distortion resistance of aPP formulationsis correspondingly low, which leads to severe limitation of the field ofuse. Pure atactic polypropylene polymers can also be prepared bymetallocene catalysis, with both very low molecular weight polymers andrelatively high molecular weight polymers being able to be obtained (L.Resconi in: “Metallocene based Polyolefins”; J. Scheirs, W. Kaminsky(editors); J. Wiley & Sons; Weinheim; 1999).

Syndiotactic polypropylene is highly transparent and displays good heatresistance, and the melting point is below that of isotacticpolypropylene. It has high rupture strengths at a moderate elongation atbreak (A. F. Mason, G. W. Coates in “Macromolecular Engineering”;Wiley-VCH, Weinheim; 2007). A disadvantage is the slow crystallizationfrom the melt observed in many cases. Owing to physical entanglement,the melt viscosity of syndiotactic polypropylene of comparable molarmass is significantly higher than that of isotactic polypropylene, i.e.the same melt viscosity can be achieved at significantly lower molarmasses. Syndiotactic and isotactic polypropylene are immiscible above aparticular molar mass, and corresponding polymer blends tend to undergophase separation. Polymer blends of syndiotactic polypropylene withother polyolefins display a significantly higher elongation at breakthan blends containing isotactic polypropylene (T. Shiomura, N.Uchikawa, T. Asanuma, R. Sugimoto, I. Fujio, S. Kimura, S. Harima, M.Akiyama, M. Kohno, N. Inoue in: “Metallocene based Polyolefins”; J.Scheirs, W. Kaminsky (editors); J. Wiley & Sons; Weinheim; 1999).Classical heterogeneous Ziegler-Natta catalysts are not able to producea syndiotactic polypropylene.

Isotactic polypropylene has a high melting point and a good tensilestrength. 100% isotactic polypropylene has a calculated melting point of185° C. and an enthalpy of fusion of about 207 J/g (J. Bicerano; J.M.S.;Rev. Macromol. Chem. Phys.; C38 (1998); 391ff). However, as homopolymerit has a relatively low-temperature resistance and a high brittlenessand poor heat sealability or weldability. The tensile strength (rupture)is about 30 MPa, and the elongation at break is virtually zero. Improvedmaterials properties can be obtained by copolymerization orterpolymerization with ethylene and 1-butene, with the comonomer contentof copolymers with ethylene usually being <8% by mass and forterpolymers with ethylene and 1-butene usually being <12% by mass.(H.-G. Elias; Makromoleküle; vol. III; Wiley-VCH; Weinheim; 2001). Atthe same MFR (Melt Flow Rate), isotactic polypropylene which has beenproduced by classical heterogeneous Ziegler-Natta catalysis has asignificantly lower pseudoplasticity then polypropylene which has beenprepared by metallocene catalysis. The impact toughness of themetallocene-based polymer is above that of the Ziegler-Natta materialover a wide molar mass range. The proportion of xylene-solubleconstituents in isotactic poly(propylene) homopolymer which has beenobtained by metallocene catalysis is usually significantly <1% by mass,while in the case of random copolymers with ethylene xylene-solublecontents of up to 5% by mass, depending on the ethylene content, havebeen found (W. Spaleck in: “Metallocene based Polyolefins”; J. Scheirs,W. Kaminsky (editors); J. Wiley & Sons; Weinheim; 1999).

Since the solubility of polypropylene depends both on the molecularweight and on its crystallinity corresponding fractionation can becarried out by means of dissolution experiments [A. Lehtinen; Macromol.Chem. Phys.; 195(1994); 1539ff].

It has been known for a long time that amorphous atactic fractions [J.Boor; “Ziegler-Natta Catalysts and Polymerization”; Academic Press; NewYork; 1979] and low molecular weight fractions having a lowcrystallinity [G. Natta, I. Pasquon, A. Zambelli, G. Gatti; Makromol.Chem.; 70 (1964); 191ff] can be obtained from polypropylene polymers byextraction with ether. Highly crystalline isotactic polymers, on theother hand, have a very low solubility both in aliphatic solvents andalso in ethers, even at elevated temperature [B. A. Krentsel, Y. V.Kissin, V. I. Kleiner, L. L. Stotskaya; “Polymers and Copolymers ofhigher 1-Olefins”; p. 19/20; Hanser Publ.; Munich; 1997]. The solublepolymer components generally have no or only very low crystallinity anddo not display a melting point [Y. V. Kissin; “Isospecificpolymerization of olefins”; Springer Verlag; New York; 1985].Polypropylene oligomers soluble in tetrahydrofuran have very low numberaverage molar masses of significantly less than 1500 g/mol [H. ElMansouri, N. Yagoubi, D. Scholler, A. Feigenbaum, D. Ferrier; J. Appl.Polym. Sci.; 71 (1999); 371ff].

The various types of polymer differ substantially in their materialsproperties. The crystallinity of highly isotactic or syndiotacticpolymers is very high because of their high order. Atactic polymers, onthe other hand, have a higher amorphous content and accordingly a lowercrystallinity. Polymers having a high crystallinity display manymaterials properties which are undesirable, especially in the field ofhot melt adhesives. Thus, for example, a high crystallinity in lowmolecular weight polymers leads to very rapid crystallization with opentimes (“open time”=period of time during which the parts to beadhesively bonded can be joined to one another) of sometimes less thanone second. This leads during application (e.g. nozzle application byspraying) to blockage of the application equipment used, even in thecase of very low temperature fluctuations, and thus to very poor processstability. In addition, there is the extremely short period of timeduring which joining of the adhesive bond can be carried out afterapplication. Highly crystalline polymers are also hard, brittle and haveonly a very low flexibility at room temperature, which is likewiseundesirable in the case of adhesive bonds. In addition, very highquantities of energy are required at the point of application or overthe entire line system to achieve melting of highly crystallinepolymers, which apart from the economic effects also has adverseconsequences for the processability.

Highly isotactic or syndiotactic polypropylene homopolymers orcopolymers with ethylene and/or higher olefins, as described in thepublications mentioned, are unsuitable for use as hot melt adhesives oradhesive raw materials.

WO 01/46278 describes 1-olefin copolymers which have predominantlyamorphous character and are obtained by metallocene catalysis. When theyare used as hot melt adhesives, no or only minimal additions of adhesiveresins are said to be necessary. The copolymers are composed of A: from60 to 94% of a C₃-C₆ 1-olefin, B: 6-40 mol % of one or more C₄-C₁₀1-olefins and optionally C: 0-10 mol % of another unsaturated monomer(preferably ethylene). The random distribution of the comonomer B has aparticularly strong disruptive effect on the crystallinity of thepolymers since only few regions now reach the minimum block lengthnecessary for crystallization (see, for example, B. S. Davison, G. L.Taylor; Br. Polym. J.; 4 (1972); 65ff). This can also be seen, interalia, from the low melting point of the polymers described. Largelyamorphous polymers also have a very unbalanced materials behaviour. Inparticular, the cohesion of such polymers is significantlyunderdeveloped in comparison to adhesion, resulting in cohesive failuresfrequently occurring when they are used for adhesive bonding. Suchpolymers having a low melting point also lead to poor heat resistance inadhesive bonds, which rules out numerous fields of use. In addition,comonomers having more than four carbon atoms are very expensive, whichmakes the products uneconomical in terms of their fields of use and theproduct prices to be achieved there. Freedom from aromatics is difficultto guarantee by means of the product process described, especially sincepolymerization is preferably carried out in aromatic solvents and thecocatalyst used does not dissolve in aliphatic solvents. The highreaction temperatures, which are (sometimes very far) above the meltingpoint of the polymers produced lead to very high reaction pressureswhich make economical operation of the polymerization process difficult.In addition, many monomers according to the invention are present in thesupercritical state in wide parts of the process window indicated(T_(R)=40-250° C., p_(R)=10-3000 bar), which requires a high engineeringoutlay for controlling the process and further restricts the economicsof the process.

There is therefore a need for floor coverings having improvedproperties. This object is surprisingly achieved by the presentinvention.

SUMMARY OF THE INVENTION

The present invention firstly provides for the use of polyolefins infloor coverings, wherein the polyolefins contain not more than 20% bymass of ethylene, either 70-100% by mass or not more than 20% by mass ofpropylene and/or either 80-100% by mass or not more than 25% by mass of1-butene, with the sum of the proportions being 100% by mass, and thetriad distribution for propene triads determined by ¹³C-NMR has anisotactic proportion of 75-98% by mass, a syndiotactic proportion of notmore than 20% by mass, an atactic proportion of less than 20% by massand/or the triad distribution for 1-butene triads determined by ¹³C-NMRhas an isotactic proportion of not more than 98% by mass and an atacticproportion of 1-85% by mass. The polyolefins mentioned are used, inparticular, as or in adhesives in the floor coverings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of monomodal molar mass distribution of theexamples;

FIG. 2 shows an example of bimodal molar mass distribution from theexamples;

FIG. 3 shows a thermogram of a polyolefin composition having a differentnumber of melting peaks;

FIG. 4 shows a relationship between complex viscosity, storage modulusand loss modulus in an embodiment of the invention;

FIG. 5 shows the relationship between complex viscosity, storage modulusand loss modulus; and

FIG. 6 shows a relationship between temperature of complex viscosity,storage modulus and loss modulus from the examples.

The polyolefins are particularly preferably used for nap and filamentbinding and/or for rear-side coating.

When used in floor coverings, the polyolefins used according to theinvention have the advantage that a property combination of low meltviscosity, high tensile strength, high flexibility/elongation at breakand high adhesive shear strength on untreated polyolefin surfaces, inparticular on untreated polyethylene and/or polypropylene, whichcombination is particularly advantageous for the intended applicationcan be achieved by means of them. In particular, the low melt viscosityprovides good and complete penetration of the raw carpet by the meltadhesive, which leads to particularly good nap or filament or fibrebinding. At the same time, the high tensile strength and the highadhesive shear strength on untreated polyolefins in combination with thehigh flexibility/elongation at break allows particularly low applicationweights, which makes the production process and the floor coveringproduced thereby particularly economical.

The floor coverings according to the invention are preferably textile ornontextile coverings; the nontextile coverings are, in particular,elastic coverings. The coverings are very particularly preferablycarpets or artificial lawns; these can be all types of carpets (e.g.tufted pile carpets, non-tufted pile carpets, tufted nonwoven carpets,etc.) and artifical lawns known to those skilled in the art.

In the polyolefins used, the triad distribution for propene triadsdetermined by ¹³C-NMR (with the proviso that the polymer containspropene triads) preferably has an isotactic proportion of 75-98% bymass, preferably 77-97% by mass, particularly preferably 79-96% by massand in particular from 80-95% by mass, based on the propene triads.

This gives the polyolefins used a high degree of cohesion without beinghard and brittle.

It is likewise preferred that the triad distribution for propene triadsdetermined by ¹³C-NMR in the polyolefins (with the proviso that thepolymer contains propene triads) has an atactic proportion of not morethan 20% by mass, preferably 1-18% by mass, particularly preferably2-16% by mass and in particular 3-15% by mass, based on the propenetriads.

This gives the polyolefins used increased adhesion and a satisfactoryflexibility in addition to the dominant cohesive materials properties.

The triad distribution for propene triads determined by ¹³C-NMR (withthe proviso that the polymer contains propene triads) preferably has asyndiotactic proportion of not more than 20% by mass, preferably 1-18%by mass, particularly preferably 2-16% by mass and in particular 3-15%by mass, based on the propene triads.

This gives the polyolefins used a high elasticity in addition to thecohesive and adhesive materials properties, and they display optimalspreading when applied as a melt. In addition, they have improvedtransparency.

In a particularly preferred embodiment of the polyolefins used, thetriad distribution for propene triads determined by ¹³C-NMR (with theproviso that the polymer contains isotactic and atactic propene triads)has a ratio of isotactic to atactic propene triads in the range from1:0.005 to 1:0.5, preferably from 1:0.01 to 1:0.45, particularlypreferably from 1:0.015 to 1:0.40 and very particularly preferably from1:0.02 to 1:0.37. This gives the polyolefins used an optimal balance ofdominant cohesive and adhesive materials properties.

The triad distribution for 1-butene triads determined by ¹³C-NMR (withthe proviso that the polymer contains 1-butene triads) particularlypreferably has a syndiotactic proportion of not more than 25% by mass,preferably 1-22% by mass, particularly preferably 2-20% by mass and inparticular 3-19% by mass, based on the 1-butene triads, where in thecase of 0% by mass of syndiotactic 1-butene triads being present, thepolymer has up to 5-85% by mass of atactic triads. This also gives thepolyolefins used an optimal wetting behaviour in addition to goodflexibility, and they additionally display optimal spreading whenapplied as a melt. In addition, they have improved transparency.

Preference is also given to the triad distribution for 1-butene triadsdetermined by ¹³C-NMR (with the proviso that the polymer contains1-butene triads) having an atactic proportion of 1-90% by mass,preferably 2-85% by mass, particularly preferably 3-82% by mass and inparticular 5-80% by mass, based on the 1-butene triads.

This enables longer open times to be achieved with the polyolefins usedas a result of slowed crystallization and thus enables the settingproperties to be matched to prevailing requirements.

Preference is also given to the triad distribution for 1-butene triadsdetermined by ¹³C-NMR (with the proviso that the polymer contains1-butene triads) having an isotactic proportion of 10-98% by mass,prefrably 15-97% by mass, particularly preferably 17-96% by mass and inparticular 19-95% by mass, based on the 1-butene triads.

Preference is additionally given to the triad distribution determined by¹³C-NMR in the examination ofpoly(ethylene-co-propylene-co-1-butene)-terpolymers prepared accordingto the invention and having ethylene contents of up to 15% by masshaving a proportion of ethylene triads of <6% by mass, preferably 0.5-5%by mass, particularly preferably 0.6-4% by mass, very particularlypreferably 0.7-3.5% by mass, based on the ethylene content, so thatalthough random incorporation of the monomer ethylene dominates, aparticular proportion of ethylene blocks is present. As a result, thepolyolefins used contain not only the relatively rigid isotacticstructural units and individual “disrupting monomer units” but alsoflexible ethylene blocks which themselves make no contribution to thecrystallinity of the overall sample but ensure balanced materialsproperties (stiffness and flexibility).

The polyolefins used preferably contain not more than 20% by mass, morepreferably not more than 18% by mass and particularly preferably notmore than 15% by mass of ethylene.

In a preferred embodiment of the present invention, the polyolefins usedcontain 100% by mass of propylene or 1-butene.

In a further preferred embodiment of the present invention, thepolyolefins used are in particular copolymers of ethylene, propyleneand/or 1-butene, with the copolymers containing not more than 20% bymass, preferably not more than 18% by mass, particularly preferably notmore than 15% by mass, of ethylene. As regards the proportion ofpropylene and butene, there are a number of alternative possibilities.The propylene content is either 70-98% by mass, preferably 72-95% bymass, or not more than 20% by mass, preferably 1-18% by mass andparticularly preferably 2-16% by mass. The butene content is either80-98% by mass, preferably 82-96% by mass, or not more than 25% by mass,preferably 1-22% by mass and particularly preferably 2-20% by mass. Thetotal proportion of all comonomers mentioned has to be 100% by mass,i.e. the polyolefins used are either relatively rich in propylene orrelatively rich in butene, with the monomers mentioned being able to becombined with one another as desired, i.e. propylene with butene and/orethylene.

In particular, the polyolefins used are poly(ethylene-co-propylene)copolymers have an ethylene content of not more than 20% by mass,poly(ethylene-co-1-butene) copolymers having an ethylene content of notmore than 15% by mass, poly(propylene-co-1-butene) copolymers having apropylene content of 2-20 or 80-98% by mass orpoly(ethylene-co-propylene-co-1-butene) terpolymers having an ethylenecontent of not more than 20% by mass.

In a particular embodiment of the present invention, the copolymerscontain propylene, 1-butene and/or ethylene and also a branched olefinselected from the group consisting of 3-methyl-1-butene,3-methyl-1-hexene, 3-methyl-1-heptene, 4-methyl-1-pentene and6-methyl-1-heptene, with the maximum proportion of the branched 1-olefinin the copolymer being not more than 50% by mass, preferably not morethan 40% by mass and particularly preferably not more than 30% by mass.

In the likewise preferred case of a terpolymer, this contains, inparticular, ethylene, propylene and 1-butene, with one of the threecomonomers having a proportion of at least 75% by mass while the othertwo monomers together make up a proportion of 25% by mass. Theterpolymers contain a proportion of not more than 20% by mass,preferably not more than 18% by mass, particularly preferably not morethan 15% by mass, of ethylene.

The following subcombinations are very particularly preferred for theabovementioned copolymers and terpolymers: poly(ethylene-co-propylene),poly(ethylene-co-1-butene), poly(propylene-co-1-butene),poly(propylene-co-3-methyl-1-butene),poly(l-butene-co-3-methyl-1-butene),poly(propylene-co-3-methyl-1-hexene),poly(propylene-co-3-methyl-1-heptene),poly(ethylene-co-propylene-co-1-butene) andpoly(ethylene-co-propylene-co-3-methyl-1-butene).

The polyolefins used are, after appropriate finishing, preferably in theform of a powder, in the form of pellets or in the form of granules.Direct further processing of molten polymer to produce the productsaccording to the invention is likewise possible.

The polyolefins used preferably do not contain any aromatic compoundsoriginating from the polymerization process (i.e. <100 μg/g).Furthermore, they contain essentially no organic halogenated compoundsoriginating from the polymerization process. It is likewise preferredthat the polymers (with the exception of the degradation productsoriginating from the catalyst decomposition) contain no contamination bysuspending oils (separation media), no residues of inorganic supportmaterials, in particular no inorganic oxides and/or alkaline metal earthhalides (e.g. MgCl₂), no inorganic or organic boron compounds, notalcites or hydrotalcites and/or their degradation products, nocontamination by alcohols, in particular by methanol. This firstlyensures that the polyolefins used are free of toxic compounds and arealso suitable in an optimal way for use in sensitive areas such ascarpet/floor coverings and/or other applications in automobileinteriors, etc. Secondly, the adverse effects which the abovementionedauxiliaries and accompanying substances have on the thermal stability(in particular colour stability) and the adhesive properties of thepolymer are ruled out.

The molar mass distribution of the polyolefins used can be monomodal orbimodal, with a narrow molar mass distribution being present even inbimodally distributed polymers.

Polymers having a narrow molar mass distribution have a small varianceof the materials properties. They have, for example, clearly definedmelting and solidification behaviour. If the molar mass distribution isvery narrow, defined melting/solidification behaviour can also beachieved in bimodally distributed polymers, particularly when relativelylong open times are required and/or no sharp melting peaks areacceptable (e.g. in the case of long joining times or a fluctuatingapplication temperature).

Furthermore, the polyolefins used have a polydispersity determined byhigh-temperature gel permeation chromatography with universalcalibration of 1.4-4, preferably 1.5-3.5. This range is particularlyadvantageous, especially for use in the adhesives sector. Thecrystallization or melting behaviour of polymers, in particularpolyolefins, is known to be a function of the molar mass; in the case oflinear polyolefins, especially the chain length. Thus, for example, itis known in the case of classical amorphous polyolefins as are used atpresent in the field of hot melt adhesives, that a polydispersity of 4-6(or even higher) leads firstly to a very broad melting range andsecondly to delayed physical hardening/crystallization. The latter isparticularly disadvantageous for hot melt adhesives which are to be usedfor the production of floor coverings, especially for the production ofcarpets and artificial lawns, because the polymers therefore have asometimes extremely long open time (i.e. the time for which the polymeris very sticky as a result of constituents which have not yetcrystallized or not yet completely crystallized). Such polymers areunsuitable for processing in carpet production, especially in cases inwhich the carpet is rolled up directly after application of the hot meltadhesive or the coating composition. An additional disadvantage of theknown systems is that polymers having a broad molar mass distributionfrequently also display poor tensile strengths as a result of theabove-described crystallization deficits, which is likewise undesirable,especially in nap and/or filament binding or carpet rear-side fixing. Ingeneral, a broad molar mass distribution is a sign that a polymermixture (or a polymer blend) rather than a uniform polymer is present,which is known to lead to impairment of the materials properties.

The weight average molar mass of the polyolefins used, determined byhigh-temperature gel permeation chromatography with universalcalibration, is usually in the range from 15000 to 200000 g/mol,preferably from 16000 to 150000 g/mol, particularly preferably in therange from 17000 to 125000 g/mol and very particularly preferably in therange from 18000 to 120000 g/mol. This range is particularlyadvantageous, especially for use in the adhesives sector. Thepolyolefins used have, owing to their molar mass and their molar massdistribution, an optimal melt viscosity in the relevant applicationwindow, so that optimal wetting of the surfaces to be adhesively bondedcan occur. In addition, the relatively low melt viscosity allowspenetration into macroscopic and microscopic surface structures, whichconsiderably improves the adhesion of the layer of adhesive. Forapplications in the field of nap and/or filament binding, the weightaverage molar mass of at least one of the polyolefins according to theinvention present is, in particular, in the range from 10000 to 50000g/mol, preferably from 10000 to 40000 g/mol, particularly preferablefrom 10000 to 35000 g/mol and very particularly preferably from 10000 to30000 g/mol. Polyolefins according to the invention having weightaverage molar masses of >75000 g/mol are also suitable, in particular,for use in moulding compositions as can be used, for example, for heavycompositions for carpets and/or carpet rear-side coatings. Polymershaving a relatively high molecular weight, especially those havingweight average molar masses of more than 200000 g/mol, have,particularly in the case of linear polyolefins, a high to very high meltviscosity. This is thoroughly desirable for many applications, e.g. theproduction of mouldings or the production of films and sheets, becausethey give the products a high stiffness and a high tensile strength.However, such materials are completely unsuitable for use as rawmaterials for hot melt adhesives. In particular, they have only slowcrystallization (as a result of chain entanglement) and cannot beapplied readily and have poor spreading behaviour even in the case ofbead application or doctor blade application. This is also to beattributed, inter alia, to the structural viscosity which isincreasingly more strongly pronounced with increasing molar mass. Inaddition, they cannot be processed at all using conventional processingand application machines in the hot melt adhesives sector because oftheir high melt viscosity; in many cases, they are not pumpable atacceptable temperatures and in addition give a very high pressurebuildup in the pipes. On the other hand, polymers having a very lowmolecular weight do not display satisfactory cohesion even in the cooledstate and have a wax-like behaviour. They are thus unsuitable for, inparticular, use in the field of hot melt adhesives. Low molecular weightconstituents also tend to migrate out by diffusion, which greatlyweakens an adhesive bond and leads to its failure. In fields wheredemanding requirements have to be met in terms of the liberation oforganic volatile materials, e.g. in the case of automobile carpets orfloor coverings for rooms of dwellings, adhesive systems or heavycompositions which have high proportions of low molecular weightcompounds can frequently also not be used for legal or regulatoryreasons.

Furthermore, the polyolefins used have an ALPHA VALUE determined byhigh-temperature gel permeation chromatography with universalcalibration in the range from 0.5 to 1.15, preferably in the range from0.55 to 1.10, particularly preferably in the range from 0.57 to 1.07 andvery particularly preferably in the range from 0.58 to 1.05. Thepolyolefins used thus have a low branching tendency, in particular theypreferably do not contain any long-chain branches. Owing to theirmolecular structure, branched polymers display highly complexrheological behaviour, which leads to difficulties in application fromthe melt, unsatisfactory penetration into the raw carpet and poorspreading, particularly in the case of doctor blade and sprayapplication.

In a particularly preferred embodiment, the ALPHA VALUE determined byhigh-temperature gel permeation chromatography with universalcalibration is in the range from 0.55 to 0.80, preferably from 0.57 to0.79 and very particularly preferably from 0.58 to 0.78, while at thesame time the polydispersity of the polymers according to the invention,likewise determined by high-temperature gel permeation chromatographywith universal calibration, is in the range from 2.0 to 3.5, preferablyfrom 2.1 to 3.4, particularly preferably from 2.2 to 3.3 and veryparticularly preferably from 2.3 to 3.2.

In a further particularly preferred embodiment, the ALPHA VALUEdetermined by high-temperature gel permeation chromatography withuniversal calibration is in the range from 0.7 to 1.1, preferably from0.75 to 1.08, particularly preferably from 0.8 to 1.06 and veryparticularly preferably from 0.82 to 1.05, while at the same time thepolydispersity of the polymers according to the invention, likewisedetermined by high-temperature gel permeation chromatography withuniversal calibration, is not more than 3, preferably not more than 2.5,particularly preferably not more than 2.3 and very particularlypreferably not more than 2.0.

The proportion of low molecular weight constituents having a molecularweight of from 500 to 1000 dalton found in the analysis by gelpermeation chromatography with universal calibration is preferably notmore than 0.75% by mass, more preferably not more than 0.70% by mass,particularly preferably not more than 0.65% by mass, in particular notmore than 0.60% by mass. It is very particularly preferred that noconstituents havng a molecular weight of from 500 to 1000 dalton can bedetected by the method described. This leads to the polyolefins usedcontaining no polymer constituents which tend to migrate to, forexample, the surface and/or the interface. Such migration (also referredto as “sweating”) leads, as a result of the removal of low molecularweight polymer constituents, to great weakening of an adhesive bondcontaining this polymer. In addition, materials containing constituentswhich migrate or are volatile at room temperature must not be used inmany fields because of legally binding regulations.

Furthermore, the proportion of low molecular weight constituents havinga molecular weight of less than 500 dalton found in the analysis byhigh-temperature gel permeation chromatography with universalcalibration is preferably not more than 0.4% by mass, more preferablynot more than 0.35% by mass, particularly preferably not more than 0.3%by mass, in particular not more than 0.25% by mass. Very particularpreference is given to no constituents having a molecular weight of lessthan 500 dalton being able to be detected by the method described. Inmotor vehicle interiors there is the problem of low molecular weightpolymer constituents having very low molar masses migrating out of theadhesive layer and vaporizing, which leads to an undesirable “fogging”phenomenon. Polymers containing low molecular weight constituents havinglow molar masses are therefore unsuitable for such applications; verystrict limits are imposed by the automobile manufacturers. The sameapplies to the field of floor coverings in rooms in dwellings andbusiness premises.

Furthermore, the polyolefins used have a complex melt viscosity of from600 to 400000 mPa*s, preferably from 700 to 300000 mPa*s, particularlypreferably from 1000 to 200000 mPa*s and very particularly preferablyfrom 1250 to 150000 mPa*s, at a temperature of 190° C., a deformation ofnot more than 1% and a measurement frequency of 1 Hz. Various ranges arevery particularly preferred depending on the desired use. Thus, forexample, for use in the field of spray application and/or for nap andfilament binding, polyolefins used according to the invention having amelt viscosity of from 600 to 10000 mPa*s, preferably from 600 to 8000mPa*s, particularly preferably from 600 to 5000 mPa*s and in particular<4000 mPa*s, are particularly preferred, while for use in mouldingcompositions (e.g. for producing heavy compositions for carpets),polymers having a melt viscosity of >40000 mPa*s, particularlypreferably >50000 mPa*s and very particularly preferably >60000 mPa*s,are particularly preferred.

In a particular, preferred embodiment, the polyolefins according to theinvention are used in the production of the floor coverings according tothe invention both for nap and/or filament binding and for carpetrear-side coating, with the properties of the polyolefins used accordingto the invention differing as follows.

In the case of nap and/or filament binding, preference is accordinglygiven to using at least one polyolefin according to the invention whichhas a weight average molar mass determined by gel permeationchromatography with universal calibration of <40000 g/mol, preferably<30000 g/mol, particularly preferably <25000 g/mol and very particularlypreferably <20000 g/mol, while at the same time the polydispersity,likewise determined by gel permeation chromatography with universalcalibration, is not more than 2.5, preferably not more than 2.3,particularly preferably not more than 2.1 and very particularlypreferably less than 2.0, while at the same time the melt viscositydetermined by oscillation rheometry (deformation not more than 1%,measurement frequency=1 Hz) at 190° C. is not more than 10000 mPa*s,preferably not more than 7500 mPa*s, particularly preferably not morethan 5000 mPa*s and very particularly preferably less than 4000 mPa*s,while at the same time the proportion of low molecular weightconstituents in the range from 1000 to 500 dalton and <500 daltondetermined by gel permeation chromatography with universal calibrationis in each case not more than 0.2% by mass, preferably in each case notmore than 0.15% by mass, particularly preferably in each case not morethan 0.1% by mass and very particularly preferably less than, in eachcase, 0.05% by mass.

In the case of carpet rear-side coating (e.g. in a heavy composition),preference is accordingly given to using at least one polyolefinaccording to the invention which has a weight average molar massdetermined by gel permeation chromatography with universal calibrationof >30000 g/mol, preferably >40000 g/mol, particularly preferably >50000g/mol and very particularly preferably >55000 g/mol, while at the sametime the polydispersity, likewise determined by gel permeationchromatography with universal calibration, is not more than 3,preferably not more than 2.8, particularly preferably not more than 2.5and very particularly preferably less than 2.2, while at the same timethe melt viscosity determined by oscillation rheometry (deformation notmore than 1%, measurement frequency=1 Hz) at 190° C. is at least 35000mPa*s, preferably at least 40000 mPa*s, particularly preferably at least50000 mPa*s and very particularly preferably greater than 60000 mPa*s,while at the same time the proportion of low molecular weightconstituents in the range from 1000 to 500 dalton and <500 daltondetermined by gel permeation chromatography with universal calibrationis in each case not more than 0.2% by mass, preferably in each case notmore than 0.15% by mass, particularly preferably in each case not morethan 0.1% by mass and very particularly preferably less than, in eachcase, 0.05% by mass.

As a measure of the pseudoplasticity of the polyolefins used, it ispossible to employ the ratio of the melt viscosity measured at 190° C.and a deformation of not more than 1% at a shear rate of 10 Hz and at ashear rate of 0.1 Hz. For the polyolefins used, this ratio is in therange from 1:1 to 1:100, preferably from 1:1.05 to 1:80, particularlypreferably from 1:1.075 to 1:60 and particularly preferably from 1:1.1to 1:40.

The polyolefins used thus have an optimal balance between processabilityand spreading properties. In particular, it is important for theprocessability of a polymer melt in the hot melt adhesives field (e.g.during spraying) that the viscosity in the application tool (e.g. spraygun) in which high shear rates usually prevail is low and the materialcan thus be transported and distributed readily. On the other hand, anincrease in the viscosity when shear is no longer present is importantfor the spreading of the applied polymer melt on the substrate so thatno spreading of the polymer melt beyond the sprayed region takes place.However, the increase has to be within narrow limits since otherwise nocoagulation of the individual spray particles takes place.

An important parameter for hot melt adhesives or adhesive raw materialsis the temperature-dependent rheological behaviour. This can bedetermined, for example, by measuring a cooling curve in an oscillatoryrheometer, with a very low deformation (max. 1%) and a slow cooling rate(1.5 K/min) being employed. The measured values obtainable from thecooling curve are significantly superior to those obtained from heatingcurves (in particular from curves during first heating) in terms oftheir reproducibility since the preceding melting firstly levels out thethermal prehistory of the polymer sample and, secondly, optimal wettingof the measurement body surface by the melt occurs, as a result of whichfrictional and slippage effects between measurement body and sample areruled out. In addition, the susceptibility to deformation (i.e. the riskof an irreversible change in morphology) of the polymer sample issignificantly lower at the high temperatures at the start of themeasurement (i.e. in the melt) than in the solid state, so that only inthis way can it be ensured that the polymer sample remains within thelinear viscoelastic region. Furthermore, it should be noted that therheological material states during adhesive bonding by means of hot meltadhesives can in any case be realistically modeled only by means of acooling curve since this is the state present during adhesive bonding.

In addition, the polyolefins used have a minimal processing temperature(“crosspoint”, intersection of storage modulus and loss modulus)determined by oscillatory rheometry at a shear rate of 1 Hz of not morethan 160° C., preferably not more than 150° C., particularly preferablynot more than 145° C. and very particularly preferably not more than140° C. The polyolefins used accordingly have optimal rheologicalprocessing properties in the processing range of 100-220° C. which isrelevant for hot melt adhesives. If the loss modulus is higher than thestorage modulus, the polymer can be induced to flow and be permanentlydeformed when shear energy is applied. On the other hand, if the storagemodulus is higher, the elastic recover forces are so great thattrouble-free application is not possible.

As rheological indication of the optimal processing window, it ispossible to employ the ratio of storage modulus and loss modulus in thetemperature range from the end of the melting point up to about 220° C.For trouble-free application from the melt, the loss modulus G″ (assynonym for the viscous materials properties) has to be significantlyabove the storage modulus G′ (as synonym for the elastic materialsproperties) in the processing window. The ratio of storage modulus G′ toloss modulus G″ for the polymers claimed at a shear rate of 1 Hz in thetemperature range from the end of the highest melting peak (offset/DSC)to about 220° C. is from 1:1 to 1:10000, preferably from 1:1.25 to1:5000, particularly preferably from 1:1.5 to 1:2500 and veryparticularly preferably from 1:2 to 1:1000.

Preference is likewise given to the minimal shear rate determined byoscillatory rheometry at or above which the loss modulus is above thestorage modulus (crosspoint) and the melt is thus rheologicallyprocessable being not more than 10 Hz, more preferably not more than 5Hz, particularly preferably not more than 1 Hz and very particularlypreferably 0.1 Hz, at the processing temperature. Thefrequency-dependent measurement of storage modulus G′ and loss modulusG″ by oscillatory rheometry (sample deformation not more than 1%) at theprocessing temperature in the frequency range from 0.1 to 10 Hz veryparticularly preferably does not have an intersection (“crosspoint”) ofG′ and G″, with G″ being greater than G′ over the entire frequencyrange. This ensures that the polyolefins used can be brought into afluid state by means of relatively little shear energy at the processingtemperature. This is particularly important when the melt is processedby spraying, both within the processing machine (where trouble-freetransport of the melt without an excessive pressure buildup is ensuredas a result) and on the surface to which the melt is applied (where theadhesive has to spread at low shear stresses).

The needle penetration of the polyolefins used is not more than 35*0.1mm, preferably 1-30*0.1 mm, particularly preferably 2-25*0.1 mm and veryparticularly preferably 3-20*0.1 mm, with ranges of 1-8*0.1 mm and10-20*0.1 mm being very particularly preferred. This ensures that thepolyolefins used have a satisfactory degree of plasticity despite highstrength. This is particularly important in application areas in whichthere is a dynamic load on the adhesive bonding. Highly crystallinepolyolefins have a needle penetration of <1*0.1 mm and are thereforevery hard and not plastically deformable, i.e. not flexible, in theunmolten state. Predominantly amorphous polyolefins have a needlepenetration of >60*0.1 mm and therefore do not display satisfactorystrength.

The polyolefins used have a predominantly partially crystalline nature,i.e. have a significant proportion of crystalline material. This isshown by the melting peak in the first and second heating of thepolymers in the DSC. Regardless of the number and sharpness of themelting peaks, the melting peak maxima for the polyolefins according tothe invention measured by means of a differential scanning calorimeter(DSC) in the first heating are in the range from 30 to 145° C.Preference is given to 1-3 melting peaks being able to be detected inthe first heating in the measurement in a differential scanningcalorimeter (DSC), with in the case of three melting peaks the firstmelting peak maximum being at temperatures of 30-80° C., the secondbeing at temperatures of 50-95° C. and the third being at temperaturesof 70-140° C., preferably at temperatures of 72-130° C. If only twomelting peaks occur, the first melting peak maximum is in the range from75 to 130° C. and the second is in the range from 90 to 140° C.,particularly preferably 92-135° C. If only one melting peak occurs, themelting peak maximum is in the range from 90 to 145° C.

Regardless of the number and sharpness of the melting peaks, the meltingpeak maxima for the polyolefins according to the invention in the secondheating in the measurement by means of a differential scanningcalorimeter (DSC) are in the range from 70 to 145° C. In the secondheating in the differential scanning calorimeter, the polymers preparedaccording to the invention preferably have 1, 2 or 3 melting peaks, within the case of three melting peaks, the first melting peak maximum beingat temperatures of 70-100° C., preferably between 72 and 95° C., thesecond at temperatures of 80-105° C., and the third at temperatures of90-140° C., particularly preferably at temperatures of 95-135° C. In thecase of two melting peaks, the first melting peak maximum is in therange from 50 to 125° C. and the second melting peak maximum is at65-140° C., particularly preferably 70-135° C. If only one melting peakis present, the melting temperature is from 75 to 145° C., particularlypreferably 78-142° C. Depending on the copolymer composition, thepolymers have a tendency to undergo cold crystallization and theexothermic cold crystallization peak (if present) in the second heatingis in the range from 15 to 40° C.

This ensures that the polyolefins used have an optimal ratio ofcrystalline and noncrystalline units and display optimal thermalproperties under load and during processing. Under load, more or lessstrongly pronounced partial melting, depending on the polymercomposition, occurs at elevated temperatures before the adhesive bondmelts completely. In this way, plastic deformation is possible withoutcomplete release (melting) of the adhesive bond, which is particularlyadvantageous in the case of structural adhesive bonds and temporaryfixing. If this is not desired, the polymers used can also be modifiedby changing polymer composition and polymerization conditions so that nosignificant partial melting takes place until just below the meltingpoint. In the latter case, very high heat distortion resistances of theadhesive bond can be achieved, with the heat distortion temperaturebeing very close to the softening temperature.

In contrast to highly crystalline polyolefins which have a single verysharp melting peak, the polyolefins used display either one meltingpeak, two melting peaks or three melting peaks in the second heatingcurve in the DSC, which can have different intensities. In the first andin the second heating curve, all polyolefins used display at least onemelting peak. The end of the melting range of the second heating curveof the DSC (known as peak offset) is in the case of the polyolefins usedin the range from 77° C. to 155° C., preferably from 79° C. to 152° C.,particularly preferably from 80° C. to 150° C. and very particularlypreferably from 82° C. to 148° C. If the end of the melting range is atlow temperatures, this is particularly advantageous for the adhesivebonding of thermolabile materials. On the other hand, if the end of themelting range is high, this results in a particularly high heatdistortion resistance.

The polymers preferably have an endothermic enthalpy of fusion measuredin the second heating in the DSC of 10 to 85 J/g, preferably 12-80 J/g,particularly preferably 14-78 J/g and very particularly preferably 16-75J/g, with the ranges of 1-15 J/g, 20-40 J/g and 50-80 J/g beingparticularly preferred. This ensures that the polyolefins used have acrystallinity which is high enough to ensure a high initial strength ofan adhesive bond. Depending on the polymer composition and thepolymerization conditions selected, it is possible to provide polymerswhich require only a moderate or else a relatively high (compared toconventional partially crystalline polyolefins) energy input to meltthem.

The exothermic enthalpy of cold crystallization measured in the secondheating in the DSC is preferably in the range 0-40 J/g, preferably 10-35J/g, particularly preferably 15-32 J/g and very particularly preferably17-30 J/g.

The glass transition temperature of the polyolefins used determined bymeans of DSC (second heating curve, 20 K/min.) is not more than −5° C.,preferably in the range from −10 to −50° C., particularly preferablyfrom −12 to −47° C. and very particularly preferably from −15 to −45° C.This ensures that the polyolefins used can, despite their crystallineisotactic proportions and depending on polymer composition andpolymerization conditions selected, also be used in fields ofapplication which demand high low-temperature flexibility and thereforeremain closed to highly crystallized polyolefins (e.g. isotacticpolypropylene). It is particularly noteworthy that the low glasstransition temperatures of the polyolefins used are achieved without theuse of expensive comonomers such as 1-pentene, 1-hexene, 1-octene,1-nonene and/or 1-decene.

Furthermore, the softening point of the polyolefins used measured by thering & ball method is, depending on the copolymer composition, not morethan 148 C, preferably 80-146° C., particularly preferably 85-144° C.and in particular from 90 to 140° C. This ensures that it is possible toprovide polymers whose adhesive bonds have an increased heat resistance.

Preference is also given to the softening temperature found (by the ring& ball method) for the polyolefins according to the invention differing,depending on the copolymer composition from the uppermost meltingtemperature (maximum melting peak) determined in the second melting inthe DSC by 1-40 K, preferably 2-35 K, particularly preferably 3-32 K.The softening temperature found (by the ring & ball method) is veryparticularly preferably 1-40 K above, preferably 3-35 K above,particularly preferably 5-30 K above, the uppermost melting temperature(maximum melting peak) determined in the second melting in the DSC. Thisensures that it is possible to provide polymers which still have goodcohesion of the material above their melting points, so that high heatdistortion resistances can be achieved.

The polyolefins used preferably have a solubility in xylene at roomtemperature of 2-100% by mass, more preferably 4-100% by mass,particularly preferably 6-100% by mass and very particularly preferably15-100% by mass, with the insolubility fractions (if they containpropene) having a proportion of isotactic propene triads of at least 75%by mass, preferably at least 80% by mass and particularly preferably atleast 82% by mass and at the same time having a proportion of atactictriads of not more than 15% by mass, preferably not more than 12% bymass and particularly preferably not more than 10% by mass, with theproportion of syndiotactic triads being <10% by mass, preferably <8% bymass, particularly preferably <6% by mass and very particularlypreferably <5% by mass. This has the advantage that, depending on thecopolymer composition and polymerization conditions selected, it ispossible to make available polymers which have moderate to very goodsolubility in xylene and, in contrast to previously known systems havingthis property, have a very narrow molar mass distribution with extremelylow proportions of low molecular weight material, and also highcrystallinity relative to the solubility and a high softening point anda moderate needle penetration. In particular, the polyolefins used whichhave a xylene solubility of 100% by mass at room temperature have anexothermic enthalpy of fusion in the second heating of the DSC of up to50 J/g, preferably up to 49 J/g, particularly preferably up to 48 J/gand very particularly preferably 1-45 J/g, with the proportion ofisotactic propene triads (if propene is present as comonomer) being notmore than 99% by mass, preferably not more than 97% by mass andparticularly preferably 70-95% by mass, based on the propene triadspresent, while the proportion of isotactic 1-butene triads (if 1-buteneis present as comonomer) is not more than 99% by mass, preferably notmore than 97% by mass and particularly preferably in the range from 60to 95% by mass, based on the 1-butene triads present. At the same time,they have a softening point determined by the ring and ball method of atleast 80° C., preferably at least 83° C., particularly preferably atleast 85° C. and very particularly preferably 85-130° C. At the sametime, they have a needle penetration of not more than 20*0.1 mm,preferably not more than 18*0.1 mm, particularly preferably not morethan 16*0.1 mm and very particularly preferably 1-15*0.1 mm. Thepolyolefins used having a high solubility in xylene make it possible toproduce solution formulations which can be handled readily and have alow toxic hazard potential.

In a particular, preferred embodiment, the polyolefins according to theinvention have a complex melt viscosity (determined at 190° C. with adeformation of not more than 1% and a measurement frequency of 1 Hz) ofnot more than 15000 mPa*s, preferably not more than 10000 mPa*s,particularly preferably not more than 7500 mPa*s and very particularlypreferably not more than 5500 mPa*s, while at the same time theirsolubility in xylene at room temperature is at least 70% by mass,preferably at least 75% by mass, particularly preferably at least 80% bymass and very particularly preferably above 90% by mass.

The polyolefins used also preferably have a solubility intetrahydrofuran at room temperature of up to 100% by mass, preferably1-100% by mass, particularly preferably 5-100% by mass and veryparticularly preferably 10-100% by mass. In a particular, preferredembodiment, the polymers according to the invention have a solubility intetrahydrofuran at room temperature of up to 60% by mass, preferably1-58% by mass, particularly preferably 2-56% by mass and veryparticularly preferably 5-55% by mass. This has the advantage that it ispossible to make available (e.g. for solvent applications) nonpolarpolymers which have a moderate to good solubility in a polar solventbut, in contrast to previously known systems having this property, havea very low molar mass distribution with extremely small proportions oflow molecular weight material, and also a high crystallinity relative tothe solubility and a high softening point and moderate needlepenetration, so that polymers which despite their solubility intetrahydrofuran have a very good cohesion of the material are provided.The polyolefins used having solubility in tetrahydrofuran also make itpossible to produce solution formulations which, owing to the lowboiling point of THF, allow very short initial drying/airing times to beachieved.

In a particular, preferred embodiment, especially when the polyolefinsaccording to the invention are used for nap and/or filament binding, atleast one of the polyolefins used according to the invention has acomplex melt viscosity (determined at 190° C. with a deformation of notmore than 1% and a measurement frequency of 1 Hz) of not more than 15000mPa*s, preferably not more than 10000 mPa*s, particularly preferably notmore than 7500 mPa*s and very particularly preferably not more than 5500mPa*s, while at the same time their solubility in xylene and THF at roomtemperature is at least 70% by mass, preferably at least 75% by mass,particularly preferably at least 80% by mass and very particularlypreferably above 90% by mass.

In addition, the polyolefins used have, without further additions ofuntreated isotactic polypropylene, an adhesive shear strength afterstorage for at least 24 hours of at least 0.20 MPa, preferably at least0.25 MPa, particularly preferably at least 0.35 MPa and in particular0.4-5 MPa. In the case of untreated polyethylene and without furtheradditions, the adhesive shear strength after storage for at least 24hours is at least 0.05 MPa, preferably at least 0.1 MPa, particularlypreferably at least 0.2 MPa and in particular more than 0.25 MPa. In thecase of untreated beech test specimens, the adhesive shear strengthwithout further additions after a storage time of at least 24 hours isat least 1.0 MPa, preferably at least 1.5 MPa, particularly preferablyat least 2.0 MPa and very particularly preferably more than 2.5 MPa. Inthe case of untreated PVC and without further additions, the adhesiveshear strength after a storage time of at least 24 hours is more than0.15 MPa, preferably at least 0.25 MPa, particularly preferably at least0.3 MPa and very particularly preferably more than 0.32 MPa.

In a very particularly preferred embodiment, the polyolefins accordingto the invention at the same time have an adhesive shear strength onuntreated beech wood and untreated isotactic polypropylene of at least0.6 MPa, preferably at least 1 MPa, particularly preferably at least 1.5MPa and very particularly preferably at least 1.75 MPa.

In a further very particularly preferred embodiment, the polyolefinsaccording to the invention have an adhesive shear strength on untreatedbeech wood of at least 1.0 MPa, preferably at least 1.5 MPa,particularly preferably at least 2 MPa and very particularly preferablyat least 2.5 MPa, while at the same time the adhesive shear strength onuntreated isotactic polypropylene is at least 1.0 MPa, preferably atleast 1.5 MPa, particularly preferably at least 2.0 MPa and veryparticularly preferably at least 2.5 MPa. The two materials “untreatedbeech wood” and “isotactic polyolefins” used here are representative ofnatural materials (beech wood) and nonpolar synthetic polymers(polypropylene) as are used in the production of floor coverings.

The open time of the polyolefins used can be, depending on polymercomposition and polymerization conditions used, up to 30 minutes. Theopen time without further additions is particularly preferably,especially when the polyolefins used are employed in nap and/or filamentbinding, not more than 300 seconds, preferably not more than 200seconds, particularly preferably not more than 150 seconds and veryparticularly preferably not more than 120 seconds, with furtherpreferred ranges being not more than 100 seconds, not more than 60seconds, not more than 45 seconds, not more than 30 seconds, not morethan 20 seconds, and in particular 1-30 seconds.

Furthermore, the polyolefins used have, without further additions, atensile strength in a tensile test after a storage time of at least 24hours of 1-25 MPa, preferably 1.2-23 MPa, particularly preferably 1.3-21MPa and in particular from 1.5 to 20 MPa, and/or an absolute elongationat break of at least 10%, preferably at least 15%, particularlypreferably 20-1500% and very particularly preferably 25 to 1250%, withranges of 50-75%, 100-650% and 150-600%, and also ranges of 150-1200%,250-1100% and 250 to 1000% likewise being particularly preferred.

In a further very particularly preferred embodiment, the polyolefinsaccording to the invention have a tensile strength of at least 1 MPa,preferably at least 2 MPa and very particularly preferably at least 4.0MPa, while at the same time the absolute elongation at break is at least100%, preferably at least 200%, particularly preferably at least 300%and very particularly preferably at least 350%, and at the same time theadhesive shear strength on untreated beech wood and untreated isotacticpolypropylene is at least 1 MPa, preferably at least 1.5 MPa,particularly preferably at least 1.75 MPa and very particularlypreferably at least 2.0 MPa.

The process for preparing the polyolefins used comprises bringing ametallocene compound, at least one first solvent which is anunhalogenated aliphatic solvent, at least one methylaluminoxanecomponent which is modified by alkyl groups and may be present insolution and/or suspension in a second solvent which is an unhalogenatedsolvent which can be identical or different to the first solvent and atleast one 1-olefin monomer into contact with one another in a reactionspace and subsequently polyermizing the at least one 1-olefin monomer ata reaction temperature to form polyolefins according to the invention,wherein the reaction temperature is above the boiling point of the firstsolvent(s).

The process mentioned has the advantage that such a process makes itpossible, in particular, for the solvent used to be separated offcompletely from the polymer. For the process described in the presentinvention, this is an essential characteristic since a major part of thesolvent can be separated off in this way in the first vaporizationstage.

At the same time, the upper temperature limit (softening point of thepolymer prepared according to the invention) avoids excessive thermalstress on the polymers produced and ensures a reaction temperature whichis optimal for the metallocene catalysts used according to theinvention.

It is important for the process that the reaction temperature in thesteady state of the reaction is above the boiling point of the firstsolvent(s) and preferably at the same time below the softening point(determined by the ring and ball method) of the polymer preparedaccording to the invention. In particular, the polymerizationtemperature in the steady state of the reaction is at least 10 K below,preferably at least 15 K below, particularly preferably at least 20 Kbelow and very particularly preferably at least 25 K below, thesoftening temperature. The latter is a particularly outstandingcharacteristic of the process according to the invention because,despite these temperature conditions, formation of macroscopic polymerparticles (as are present, for instance, in a slurry polymerization) inthe polymerization medium does not occur but instead polymerizationoccurs in a homogeneous phase when the process according to theinvention is employed.

A further important characteristic of the process is that thepolymerization temperature is particularly preferably below thesoftening point of the prepared polymer.

The at least one first solvent is selected from among unhalogenatedcyclic and/or linear aliphatic solvents. The solvent preferably has aboiling point at atmospheric pressure of not more than 101° C. Thealiphatic solvents preferably have a boiling point at atmosphericpressure of not more than 80° C., preferably not more than 60° C.,particularly preferably not more than 40° C. and very particularlypreferably not more than 20° C.

In particular, the unhalogenated aliphatic solvents are cyclic and/orlinear aliphatic compounds having not more than 7 carbon atoms,preferably not more than 6 carbon atoms and particularly preferably notmore than 5 carbon atoms. The unhalogenated aliphatic solvent isparticularly preferably selected from the group consisting of propane,butane, pentane, cyclopentane, methylcyclopentane, hexane, cyclohexane,methylcyclohexane, heptane and mixtures thereof. The solvent is veryparticularly preferably propane and/or n-butane.

The metallocene compound which is preferably used in the present processis selected from among compounds of the formula IZ_(x)R¹R^(1a)YR²R^(2a)(IndR³R⁴R⁵R⁶R⁷R⁸)₂MCl₂  I

where M is a transition metal selected from the group consisting of Zr,Hf and Ti, preferably Zr, and Ind is indenyl and Z_(x)R¹R^(1a)YR²R^(2a)is a bridge connecting the indenyl radicals, where Z and Y are selectedfrom among carbon and silicon, x=0 or 1 and R¹, R^(1a) and R² and R^(2a)are selected independently from among H, linear or branched alkyl groupshaving from 1 to 6 carbon atoms, alkoxyalkyl groups having from 1 to 6carbon atoms, aryl groups or alkoxyaryl groups having from 6 to 10carbon atoms, and R³ to R⁸ are selected from the group consisting of Hand linear or branched alkyl groups having from 1 to 10 carbon atoms,alkylaryl groups, arylalkyl groups or aryl groups having from 6 to 10carbon atoms.

The radicals R³, R⁵ and/or R⁷ are preferably selected from the groupconsisting of H and linear or branched alkyl groups having from 1 to 10carbon atoms and aryl groups having from 6 to 10 carbon atoms, inparticular linear or branched alkyl groups having from 1 to 10 carbonatoms. If R⁶ and R⁷ are both not substituted by H, then R⁶ and R⁷ areparticularly preferably joined to one another, in particular in the formof a fused benzene ring. Particular preference is given to R³ to R⁸being hydrogen, i.e. the indenyl ring is unsubstituted. In a particularembodiment, the indenyl ligands are tetrahydroindenyl ligands.

The metallocene compound is preferably one of the formula II,

where R¹ to R⁸ are as defined above.

Linear and branched alkyl groups having from 1 to 10 carbon atoms are,in particular, substituents selected from the group consisting ofmethyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, hexyl,heptyl, octyl, nonyl and decyl.

Alkoxyalkyl groups having from 1 to 6 carbon atoms are, in particular,selected from the group consisting of methoxymethyl, methoxyethyl,methoxypropyl, ethoxymethyl, ethoxyethyl and ethoxypropyl.

Aryl groups having from 6 to 10 carbon atoms are, in particular,selected from the group consisting of benzyl, phenyl and indenyl.

Alkylaryl groups having from 6 to 10 carbon atoms are, in particular,selected from the group consisting of methylenephenyl, methyleneindenyland ethylbenzyl.

Arylalkyl groups having from 6 to 10 carbon atoms are, in particular,selected from the group consisting of methylphenyl, dimethylphenyl,ethylphenyl, ethylmethylphenyl and methylindenyl.

Alkoxyaryl groups having from 6 to 10 carbon atoms are, in particular,selected from the group consisting of methoxyphenyl, dimethoxyphenyl,ethoxyphenyl, methoxyethoxyphenyl and methoxyindenyl where the alkoxygroup is preferably located in the para position relative to the pointof linkage of the alkoxyaryl group to the metallocene.

In particular, Z_(x)R¹R^(1a)YR²R^(2a) is selected from the groupconsisting of —CH₂—, —HCCH₃—, —C(CH₃)₂—, —CH₂CH₂—, —C(CH₃)₂C(CH₃)₂—,—CH₂C(CH₃)₂—, —Si(CH₃)₂—, —Si(CH₃)₂Si(CH₃)₂—, —Si(CH₃)₂C(CH₃)₂—,—C(CH₃)₂Si(CH₃)₂—, —C(C₆H₅)₂—, —C(C₆H₄OCH₃)₂—, —C(OCH₂C₆H₅)₂—,—C(OCH₃)₂—, —C(OCH₃)₂C(OCH₃)₂, and —CH₂C(OCH₃)₂—.

The metallocene compound in the present process is very particularlypreferably diphenylsilylbis(indenyl)zirconium dichloride,dimethyl-methylenebis(indenyl)zirconium dichloride,dimethylsilylbis(2-methyl-inedenyl)zirconium dichloride,dimethylsilylbis(2-methyl-4,6-diisopropyl-indenyl)zirconium dichloride,dimethylsilylbis(2-methylbenzoindenyl)zirconium dichloride,ethylidenebis(indenyl)zirconium dichloride orethylidenebis(tetra-hydroindenyl)zirconium dichloride.

The compounds mentioned are preferably present as a racemic mixture ofenantiomers and particularly preferably do not contain a significantproportion of the enantiomorphic, optically inactive meso form. Theproportion of the meso form in the present invention is not more than 5%by mass, preferably not more than 2% by mass and particularly preferablynot more than 1% by mass.

The catalyst is preferably introduced into the polymerization spacetogether with a large excess of aliphatic hydrocarbon(s), particularlypreferably the first solvent, and is particularly preferably introducedin homogeneous form, i.e. completely in solution.

The 1-olefin monomers used in the polymerization can in principle beselected from among all 1-olefins known to those skilled in the art. Inparticular, the at least one 1-olefin monomer is selected from the groupconsisting of ethylene and linear 1-olefins. Suitable linear 1-olefinsare, in particular, propene and/or 1-butene.

In carrying out the reaction of the process, the metallocene compoundand the at least one methylaluminoxane component modified by alkylgroups are preferably fed in homogeneous form into the reaction space.This is effected, in particular, by the metallocene compound beingpresent in solution in the first solvent and the at least onemethylaluminoxane component modified by alkyl groups being present insolution in the second solvent and the two solutions being fed togetherinto the reaction space, with mixing of the two feed streams preferablytaking place only immediately before entry into the reaction space oronly in the reaction space itself, particularly preferably only in thereaction space itself. The (metallocene) catalyst feed fed preferablydoes not contain any aluminium compounds. This has the advantage that nouncontrolled preactivation and/or secondary reaction of metallocenecatalyst and cocatalyst, which can lead to poorly reproducible catalystactivities and polymerization results, takes place.

The at least one methylaluminoxane component modified by alkyl groupsserves as cocatalyst in the process according to the invention. Inparticular, the cocatalyst is a compound of the formula III for thelinear type

and/or of the formula IV for the cyclic type

where, in the formulae III and IV, R⁸ is methyl and/or isobutyl and n isan integer from 2 to 50. In particular, from 15 to 45 mol % of theradicals R⁸ are isobutyl, preferably from 17 to 45 mol %, particularlypreferably from 19 to 43 mol % and very particularly preferably from 20to 40 mol %. Only the proportion of isobutyl radicals makes thecocatalyst soluble in nonaromatic solvents. The cocatalyst is preferablypresent in solution in a second solvent whose boiling point is veryparticularly preferably not more than 101° C. The second solvent of thecocatalyst is, in particular, selected from among linear alkanes having3-7 carbon atoms, preferably 4-6 carbon atoms, with the boiling point ofthe second solvent preferably being significantly below thepolymerization temperature, but this is not absolutely necessary. Thesecond solvent is particularly preferably propane, n-butane, n-pentane,cyclopentane, methylcyclopentane, n-hexane, cyclohexane,methylcyclohexane and/or n-heptane.

The proportion of the second solvent in the total amount of solvent inthe polymerization is very small, preferably below 5% by mass, inparticular below 2% by mass. Even if the second solvent has a boilingpoint higher than the polymerization temperature selected, theabove-described advantages according to the invention are neverthelessachieved since the proportion of the second solvent is very low and ittherefore has essentially no influence on the course of thepolymerization.

Overall, the use of aromatic and/or halogenated, in particularchlorinated, solvents is avoided over the entire course of the processaccording to the invention and only unhalogenated, aliphatic solventsare used. Preference is given to using no hydrocarbon compound havingmore than 7 carbon atoms as solvent, suspension medium and/or monomerduring the entire polymerization process.

The reaction space for carrying out the process can be a stirred vessel,a cascade of stirred vessels having at least two stirred vessels, a flowtube and/or a flow tube with forced transport (e.g. a screw apparatus).The abovementioned reactors can be used either as single items or in anycombination.

Furthermore, preference is given to using no separation agents such asoils and/or waxes in the process, either before or during thepolymerization and/or the removal of solvent/monomer. This has theadvantage that the polymer according to the invention does not containany separation agents which influence the adhesive properties in anundesirable way and lead to poor performance in the end product. Theremoval of the separation agents at greatly elevated temperatures (riskof product discoloration) and/or very low pressures(complicated/expensive technology) or purification of the polymers byreprecipitation and/or extraction (complicated/expensive technology)which would otherwise be necessary can be dispensed with.

The polymers prepared in this way can be chemically stabilized accordingto the prior art either in the form of their reaction solution or at alater point in time in order to protect them against the effects ofsunlight, atmospheric moisture and oxygen. Here, it is possible to use,for example, stabilizers containing hindered amines (HALS), hinderedphenols, phosphites and/or aromatic amines. The active amount ofstabilizers is in the range from 0.1 to 3% by weight, based on thepolymer.

In particular cases, it is possible to use antifogging substances asadditives. It is here possible to use, for example, fatty acid esters;the active concentrations generally are in the range from 0.1 to 2% byweight, based on the polymer. The polymer obtained according to theinvention is obtained after the polymerization either by precipitationin a differently polar precipitate (for instance water and/or alcoholssuch as ethanol, isopropanol or butanol) or by direct devolatilizationwith a subsequent melting step. In both cases, it is possible to useeither stirred vessels or cascades of stirred vessels or else flow tubesor tubular reactors with forced transport (for example a screwapparatus). In the latter case, the use of multiscrew apparatuses isparticularly preferred.

Subsequent to devolatilization, the polymer produced can be subjected tofurther finishing treatment which can be addition of additives and/orpulverization and/or pelletization and/or granulation. Direct dispensingof the molten polymer into heated transport containers is likewisepossible.

Granulation can be strand granulation or underwater granulation, inparticular underwater strand granulation or underwater die-facegranulation. The use of a surfactant and/or dispersant or a separationagent emulsion may be necessary. The use of liquified or low-temperaturegases such as CO₂ and/or N₂ as coolant is also possible. Pulverizationcan be carried out either by a separate milling step or by use of aspray method. In both cases, the use of supercritical fluids such asCO₂, water or propane is also possible. In these processes, which areknown, for example, under the name PGSS (“particle from gas saturatedsolutions”), the polymer melt is mixed with a supercritical medium andsubsequently atomized in a spray tower. Here, the particle sizes can becontrolled via the nozzle and tower geometry. The milling process canalso be carried out using low-temperature gases such as CO₂ and/or N₂.

To ensure flowability of the granulated material and/or powder, the flowimprovers usually used in the polymer sector can be used. These can beeither inorganic or organic in nature and contain either low molecularweight components or high molecular weight components. In both cases,both crystalline and amorphous flow improvers can be used. The flowimprovers can be compatible or incompatible in terms of themodynamicmiscibility with the polymers prepared according to the invention.Particular preference is given to flow improvers which are compatiblewith the polymers prepared according to the invention and do not impairthe adhesive properties of the polymers because of their chemical natureand/or their low proportion based on the mass of the polymer accordingto the invention. As flow improvers, it is possible to use, for example,polyolefin waxes (both polyethylene-based waxes and polypropylene-basedwaxes) and also Fischer-Tropsch waxes. Polyolefin waxes based on1-butene can also be used. It is likewise possible to use microwaxes.Apart from waxes, it is also possible to use olefin polymers such aspolyethylene, polypropylene and/or poly(1-butene), in particularisotactic or syndiotactic polypropylene. Both waxes and polymers canalso be used in modified form (e.g. modified by means of maleicanhydride). The use of crosslinked polymers such as crosslinkedpolyolefins or crosslinked styrene-divinylbenzene polymers in thepolymerized state is also possible. Possible inorganic materials are,for example, MgO, talc, silica, etc.

The polyolefins used are preferably employed as or in adhesives orcoating compositions for production of the floor coverings according tothe invention, particularly preferably in adhesive and coatingformulations. The adhesive and coating formulations preferred accordingto the invention comprise essentially the polymer according to theinvention.

Apart from the polyolefins used, further constituents can be present inthe adhesive formulations according to the invention. The furtherconstituents can be, particularly in the case of solution formulations,cyclic and/or linear aliphatic and/or aromatic hydrocarbons and alsocorresponding halogenated hydrocarbons. Here, the good solubility of thepolyolefins used in various solvents such as xylene and tetrahydrofuranproves to be particularly advantageous. It is therefore not necessary tochoose halogenated solvents in order to be able to produce a solutionformulation. Preference is therefore given to using no halogenatedhydrocarbons. In the adhesive formulations which are liquid at roomtemperature, the hydrocarbons mentioned are present in a proportionbased on the formulation of not more than 90% by mass, preferably notmore than 80% by mass, particularly preferably not more than 75% by massand very particularly preferably not more than 50% by mass.

The adhesive formulation is very particularly preferably a hot meltadhesive formulation. The coating compositions are very particularlypreferably heavy coating compositions which are applied from the melt.

The hot melt adhesive formulation or coating formulation can containfurther constituents which are necessary to achieve specific propertiessuch as deformability, adhesive capability, processability, (melt orsolution) viscosity, strength, crystallization rate, tack, storagestability, etc. In a particular embodiment of the present invention, theproportion of further constituents is particularly preferably not morethan 10% by mass. This has the advantage that the materials propertiesof the adhesive formulation are essentially those of the polymeraccording to the invention which is used. Such an adhesive or coatingformulation can be produced with very little outlay.

In a further, alternative embodiment of the present invention, theproportion of further constituents can be >10% by mass. In this case,the further constituents make up not more than 80% by mass of the totalformulation, preferably not more than 60% by mass, particularlypreferably not more than 50% by mass, very particularly preferably notmore than 40% by mass.

The further constituents can be inorganic and/or organic fillers whichmay be, as desired, electrically conductive or insulating, inorganicand/or organic pigments which may be, as desired, electricallyconductive or insulating, synthetic and/or natural resins, in particularadhesive resins, synthetic and/or natural oils, inorganic and/ororganic, synthetic and/or natural polymers which may be, as desired,electrically conductive or insulating, inorganic and/or organic,synthetic and/or natural fibres which may be, as desired, electricallyconductive or insulating, inorganic and/or organic stabilizers,inorganic and/or organic flame retardants.

In particular, the further constituents encompass resins which are usedto match particular properties of the adhesive layer, in particular thetack and/or adhesion, the flow and creep behaviour of the adhesive layerand/or the viscosity of the adhesive to particular applications. Theresins can be natural resins and/or synthetic resins. In the case ofnatural resins, these natural resins contain abietic acid as mainconstituent (e.g. rosin). The resins can also be terpene or polyterpeneresins, petroleum resins and/or coumarone-indene resins, in particularC₅ resins and/or C₉ resins and/or copolymers of C₅/C₉ resins. Theproportion of the resins in the hot melt adhesive formulation accordingto the invention is, in particular, not more than 45% by mass,preferably from 1 to 40% by mass, particularly preferably from 2 to 30%by mass and very particularly preferably from 3 to 20% by mass, based onthe total formulation.

Furthermore, classical amorphous poly(α-olefins) (known as APAOs) can bepresent as further constituents in the hot melt adhesive formulations ofthe invention. The amorphous poly(α-olefins) mentioned can behomopolymers, copolymers and/or terpolymers of ethylene, propylene,1-butene and linear and/or branched 1-olefins having 5-20 carbon atomswhich can be obtained, for example, by classical Ziegler-Natta catalysisor metallocene catalysis. The proportion of amorphous poly(α-olefins)is, in particular, not more than 50% by mass, preferably not more than40% by mass and particularly preferably not more than 30% by mass, basedon the total formulation. The further constituents are preferablycrystalline or partially crystalline polyolefins, in particularisotactic polypropylene, syndiotactic polypropylene, polyethylene (HDPE,LDPE and/or LLDPE), isotactic poly(1-butene), syndiotacticpoly(1-butene), their copolymers and/or their copolymers with linearand/or branched 1-olefins having from 5 to 10 carbon atoms. Preferenceis also given to the crystalline or partially crystalline polyolefinsbeing chemically modified polyolefins, with the chemical modificationbeing, in particular, modification by maleic anhydride, itaconicanhydride, acrylic acid, acrylates, methacrylates, unsaturated epoxycompounds, silanacrylates, silanes and hydroxyalkylsilanes.

Furthermore, the further constituents can comprise polymers having polargroups. Polymers having polar groups include polystyrene copolymers(e.g. with maleic anhydride, acrylonitrile, etc.), polyacrylates,polymethacrylates, (co)polyesters, polyurethanes, (co)polyamides,polyether ketones, polyacrylic acid, polycarbonates and chemicallymodified polyolefins (e.g. poly(propylene-graft-maleic anhydride) orpoly(propylene-graft-alkoxyvinylsilane).

Furthermore, the further constituents can comprise homopolymers and/orcopolymers based on ethylene, propylene, acrylonitrile, butadiene,styrene and/or isoprene, in particular block copolymers, especiallyrubbers such as natural and synthetic rubber, poly(butadiene),poly(isoprene), styrene-butadiene rubber and nitrile rubber. Theproportion of polymers based on butadiene, styrene and/or isoprene isnot more than 20% by mass, preferably 1-15% by mass, particularlypreferably 1.5-10% by mass and in particular 2-9% by mass, based on thehot melt adhesive formulations.

Furthermore, the further constituents can comprise elastomeric polymersbased on ethylene, propylene, a diene and/or cis,cis-1,5-cyclooctadiene,exo-dicyclopentadiene, endo-dicyclopentadiene and 1,4-hexadiene and5-ethylidene-2-norbornene, in particular ethylene-propylene rubber, EPM(double-bond-free, ethylene content=40-75% by mass) and/or EPDM. Theproportion of polymers based on ethylene, propylene, a diene and/orcis,cis-1,5-cyclooctadiene, exo-dicyclopentadiene,endo-dicyclopentadiene, 1,4-hexadiene and 5-ethylidene-2-norbornene isusually not more than 20% by mass, preferably 1-15% by mass,particularly preferably 1.5-10% by mass and in particular 2-9% by mass,based on the hot melt adhesive formulations.

As an alternative, the further constituents can comprise waxes, inparticular modified and unmodified waxes, preferably crystalline,partially crystalline and/or amorphous polyolefin waxes based onpolyethylene, polypropylene and/or poly(1-butene), paraffin waxes,metallocene waxes, microwaxes, polyamide waxes, polytetrafluoroethylenewaxes and/or Fischer-Tropsch waxes. The proportion of waxes is not morethan 50% by mass, preferably 1-40% by mass, particularly preferably2-30% by mass and very particularly preferably 3-20% by mass, based onthe hot melt adhesive formulations.

Furthermore, the further constituents can comprise fillers which areused to match specific property profiles of the layer of adhesive, e.g.the temperature range in which it can be used, the strength, theshrinkage, the electrical conductivity, the magnetism and/or the thermalconductivity, to specific applications in a targeted manner. Inparticular, use is made of fillers in the production of heavy coatingsfor carpets. In general, the fillers are inorganic and/or organicfillers. The inorganic fillers are, in particular, selected from amongsilicas (including hydrophobicized silicas), quartz flour, chalks,barite, glass particles (in particular spherical particles forincreasing the reflection of light), glass fibres, carbon fibres,asbestos particles, asbestos fibres and/or metal powders. Organicfillers are, for example, carbon black, bitumen, crosslinkedpolyethylene, crosslinked caoutchouc or rubber mixtures, syntheticfibres such as polyethylene fibres, polypropylene fibres, polyesterfibres, polyamide fibres, aramid fibres, Saran fibres, MP fibres ornatural fibres such as straw, wool, cotton, silk, flax, hemp, juiceand/or sisal. The proportion of fillers is not more than 80% by mass,preferably 1-60% by mass, particularly preferably 5-40% by mass and veryparticularly preferably 7-30% by mass, based on the hot melt adhesiveformulations.

The further constituents can likewise comprise stabilizers which areused to protect the adhesive formulation against external influencessuch as the effect of (processing) heat, shear stress, sunlight,atmospheric moisture and oxygen. Suitable stabilizers are, for example,hindered amines (HALSs), hindered phenols, phosphites and/or aromaticamines. In the formulations mentioned, the proportion of stabilizers isnot more than 3% by mass, preferably from 0.05 to 2.5% by mass and veryparticularly preferably from 0.1 to 2% by mass, based on the hot meltadhesive formulations.

In addition, the further constituents can comprise one or more oilswhich can be natural and/or synthetic oils. These one or more oilspreferably have a viscosity at the processing temperature of from 1 to1000 mPa*s, preferably 2-750 mPa*s, most preferably 3-500 mPa*s.Suitable oils are, for example, mineral oils, (medical) white oils,isobutene oils, butadiene oils, hydrogenated butadiene oils and/orparaffin oils. The proportion of the one or more oils is not more than50% by mass, preferably 1-45% by mass, particularly preferably 3-40% bymass and in particular 5-38% by mass, based on the hot melt adhesiveformulations.

Furthermore, inorganic and/or organic pigments, UV active substances,organic and/or inorganic nucleating agents which accelerate thecrystallization of the polymers and thus reduce the open time of theadhesive bond can be present in the hot melt adhesive formulations.

In a further preferred embodiment of the hot melt adhesive formulationsof the invention, the above-described formulations are multiphaseblends.

The abovementioned hot melt adhesive formulations are used particularlyfor the production of floor coverings, with the formulations being usedfor nap and filament binding and/or for rear-side coating.

In the case of nap and filament binding, it is usual to use fibres orfibre composites based on natural and/or synthetic fibres. Examples ofnatural fibres or fibre composites are wool, cotton, sisal, jute, straw,hemp, flax, silk and/or mixtures of these fibres.

Examples of synthetic fibres or fibre composites to be bound in are(co)polyamide fibres, polyethylene fibres, co(polyester) fibres,polypropylene fibres and/or mixtures of these fibres. In the case ofartificial lawn bonding, the filaments bound in by the adhesive bond areselected from among polypropylene filaments, polyethylene filaments,polyamide filaments, polyester filaments or mixed filaments of thepolymers listed.

In the abovementioned applications for nap and filament binding, thelower limit to the melt viscosity of the polyolefin(s) according to theinvention present is 190° C. Preference is given to at least one of thepolyolefins according to the invention present having a melt viscosityat 190° C. of not more than 10000 mPa*s, preferably from 500 to 8000mPa*s, particularly preferably from 600 to 6000 mPa*s and veryparticularly preferably from 750 to 4000 mPa*s. In the case of theformulations or coating compositions containing at least one polyolefinaccording to the invention which are used for nap and/or filamentbinding, the melt viscosity at 190° C. is in the range from 200 to 8500mPa*s, preferably from 300 to 6500 mPa*s, particularly preferably from400 to 5000 mPa*s and very particularly preferably from 500 to 4000mPa*s. The proportion of polyolefins according to the invention is, inparticular, 60-98% by mass. The application weight is, in particular,20-1500 g/m², preferably from 50 to 1250 g/m², particularly preferablyfrom 75 to 1000 g/m² and very particularly preferably from 80 to 500g/m². In a particular embodiment, especially when polyolefins having amelt viscosity at 190° C. of <6000 mPa*s are used, the applicationweight is less than 750 g/m², preferably less than 650 g/m²,particularly preferably less than 500 g/m² and very particularlypreferably less than 450 g/m².

The hot melt adhesive or the coating composition is preferably appliedto the rear side of the raw carpet (e.g. needle felt, tufting, velour,loop wear, etc.), with the hot melt adhesive or coating compositionpreferably being present in molten form. As methods of application, itis possible to use all methods known to those skilled in the art, inparticular multiroller application, doctor blade application, sprayapplication, roller application and application by means of a slitnozzle (e.g. in combination with an additional doctor blade and/or anembossing roller). In a particular embodiment, application takes placeusing a melt extruder in combination with a slit nozzle. In a furtherparticular embodiment, further coatings are applied simultaneously or insuccession by coextrusion. In particular, the use of roller applicationmethods makes it possible to achieve particularly low applicationweights. The application temperature depends firstly on the thermalstability of the raw carpet used (in particular the thermal stability ofthe carpet colorant or further additives used), and secondly on thethermal (e.g. melting point) and rheological (e.g. melt viscosity)properties of the polyolefin according to the invention which is used.The application temperature in the case of hot melt adhesives or coatingcompositions which are solid at room temperature is preferably above thesoftening temperature of the hot melt adhesives or coating compositionsused, particularly preferably in the range from 80 to 250° C., veryparticularly preferably in the range from 95 to 200° C. In a particularembodiment, in particular when the raw carpet contains polyolefin fibressuch as polypropylene fibres and/or natural fibres, the applicationtemperature is in the range from 100 to 200° C., preferably from 105 to195° C., particularly preferably from 110 to 190° C. and veryparticularly preferably from 115 to 185° C. In a further particularembodiment, especially when the raw carpet contains polyamide fibres, inparticular fibres composed of polyamide-6,6, it is also possible to usesignificantly higher application temperatures. For example, theapplication temperature in this case is >150° C., preferably >160° C.,particularly preferably in the range from 165 to 295° C. and veryparticularly preferably from 170 to 275° C. Before application of thecoating composition, the raw carpet or the floor covering can bepreheated, preferably using infrared radiation as heat source. Thepreceding heating of the raw carpet or the floor covering isparticularly advantageous when particularly complete or deep penetrationof the hot melt adhesive used or the coating composition used isdesired. In a particular embodiment, heated rollers and/or rolls areused for preheating of the raw carpet, resulting in particularlyintimate contact and particularly good heat transfer.

The coating weight (amount of hot melt adhesive or coating compositionper unit area) required is dependent, in particular, on the type andform of the raw carpet used or the floor covering used. In particular,it is dependent on the thickness of the nap, with thick nap generallyrequiring a thicker application (i.e. a higher coating weight). It isalso dependent on the nap density, with the coating weight generallyincreasing with increasing number of nap threads per unit area.

After application of the coating composition, the carpet or the floorcovering can be subjected to a subsequent heat treatment which prolongsthe flowability of the hot melt adhesive used or the coating compositionused and thus allows particularly complete or deep penetration of thehot melt adhesive used or the coating composition used. Preference isgiven to using infrared radiation as heat source for the subsequent heattreatment, but the use of other heat sources such as hot air or steamand/or other heat sources is likewise possible. In a particularembodiment, heated rollers and/or rolls are used for the subsequent heattreatment of the carpet or floor covering, resulting in particularlyintimate contact and particularly good heat transfer. In particular, theadditional pressure gives particularly good penetration and distributionof the hot melt adhesive used or the coating composition used and thusallows particularly low application weights. In a further particularembodiment, the rolls or rollers used for the preheating and/or theapplication of the hot melt adhesive or the coating composition and/orthe subsequent heat treatment have different temperatures, as a resultof which precise control of the penetration and/or coating process isachieved.

As an alternative or in addition, the polyolefins are used, particularlyin the form of adhesives, for rear-side coating.

In a particularly preferred embodiment of the present invention, pilethreads and/or pile loops are bound in and a textile substrate and/or anonwoven and/or a felt and/or a foam are laminated on simultaneously orimmediately after one another in one working step. The laminated-ontextile substrate or the nonwoven or the felt can consist of one or moredifferent materials, in particular natural and/or synthetic inorganicand/or organic materials such as wool, cotton, sisal, jute, straw, hemp,flax, silk, (co)polyamide, polyethylene, co(polyester), polypropyleneand/or mixtures of these materials. As an alternative thereto or inaddition, a heavy coating composition can also be applied using the sameapplication system. In a particularly preferred embodiment, the hot meltadhesive used or the coating composition used is selected so that rapidsolidification occurs after application, so that the carpet can berolled up immediately after production. In a further particularlypreferred embodiment, the nap and/or filament binding of the raw carpetis effected using at least one polymer according to the invention, withthe semifinished carpet which has been fixed in this way being rolled upimmediately after fixing. In a separate working step, a heavy coatingcomposition which preferably likewise contains at least one polyolefinaccording to the invention is subsequently applied and the heavy-coatedcarpet is subsequently shaped, e.g. by stamping.

The present invention further provides floor coverings containingpolyolefins, wherein the polyolefins contain not more than 20% by massof ethylene, either 70-100% by mass or not more than 20% by mass ofpropylene and/or either 70-100% by mass or not more than 20% by mass of1-butene, with the sum of the proportions being 100% by mass, and thetriad distribution for propene triads determined by ¹³C-NMR has anisotactic proportion of 75-98% by mass, an atactic proportion of lessthan 20% by mass and a syndiotactic proportion of not more than 20% bymass and/or the triad distribution for 1-butene triads determined by¹³C-NMR has an isotactic proportion of 10-98% by mass, an atacticproportion of 1-85% by mass and a syndiotactic proportion of not morethan 20% by mass.

In particular, the floor coverings are carpets or artificial lawns.

The carpet elements are, for example, meter ware, carpet nonwovens or asubsequently shaped automobile carpet.

Even without further information, it is assumed that a person skilled inthe art can utilize the above description in its widest scope. Thepreferred embodiments and examples are therefore to be interpretedmerely as descriptive, but not in any way limiting disclosure.

The present invention is illustrated below with the aid of examples.Alternative embodiments of the present invention can be obtained in ananalogous manner.

EXAMPLES

Analysis:

a) High-temperature ¹³C-NMR

The polymer composition is determined by high-temperature ¹³C-NMR.¹³C-NMR spectroscopy of polymers is described, for example, in thefollowing publications:

-   -   [1] S. Berger, S. Braun, H.-O. Kalinowski,        ¹³C-NMR-Spektroskopie, Georg Thieme Verlag Stuttgart 1985    -   [2] A. E. Tonelli, NMR Spectroscopy and Polymer Microstructure,        Verlag Chemie Weinheim 1989    -   [3] J. L. Koenig, Spectroscopy of Polymers, ACS Professional        Reference Books, Washington 1992    -   [4] J. C. Randall, Polymer Sequence Determination, Academic        Press, New York 1977    -   [5] A. Zambelli et al: Macomolecules, 8, 687 (1975)    -   [6] A. Filho, G. Galland: J. Appl. Polym. Sci., 80, 1880 (2001)

b) High-Temperature GPC

The molecular weight is determined by high-temperature GPC. Thedetermination is carried out as described in ASTM D6474-99 but at ahigher temperature (160° C. instead of 140° C.) and using a lowerinjection volume of 150 μl instead of 300 μl. As further references onthe subject of GPC analysis of polymers, mention may be made of:

H. G. Elias: “Makromoleküle”; vol. 2; Wiley-VCH; Weinheim 2001;

Z. Grubisic, P. Rempp, H. Benoit; Polym. Lett.; 5; 753 (1967);

K. A. Boni, F. A. Sliemers, P. B. Stickney; J. Polym. Sci.; A2; 6; 1579(1968);

D. Goedhart, A. Opschoor; J. Polym. Sci.; A2; 8; 1227 (1970);

A. Rudin, H. L. W. Hoegy; J. Polym. Sci.; A1; 10; 217 (1972);

G. Samay, M. Kubin, J. Podesva; Angew. Makromol. Chem.; 72; 185 (1978);

B. Ivan, Z. Laszlo-Hedvig, T. Kelen, F. Tüdos; Polym. Bull.; 8; 311(1982);

K.-Q. Wang, S.-Y. Zhang, J. Xu, Y. Li, H. P. Li; J. Liqu. Chrom.; 5;1899 (1982);

T. G. Scholte, H. M. Schoffeleers, A. M. G. Brands; J. Appl. Polym.Sci.; 29; 3763 (1984).

Trichlorobenzene is used as solvent. The measurement is carried out at acolumn temperature of 160° C. The universal calibration used forevaluating the elution curves is carried out using polyolefin standards.The results are not comparable with measurements whose calibrations havebeen carried out using different types of polymers, e.g. polystyrene, orwhich have been made without universal calibration, since otherwise animpermissible comparison of different three-dimensional polymerstructures or hydrodynamic radii would occur. Comparison withmeasurements using solvents other than the solvent indicated is also notpermissible since different three-dimensional polymer structures orhydrodynamic radii can be present in different solvents and would leadto a different result in the molecular weight determination.

The polydispersity P_(d) is the ratio of number average molar mass toweight average molar mass. It is, in particular, a measure of the widthof the molar mass distribution present, which in turn allows conclusionsregarding the polymerization behaviour to be drawn. It is determined byhigh-temperature GPC. The polydispersity is, within certain limits,characteristic of a particular catalyst/cocatalyst combination. Thepolydispersity has a relatively strong influence on the tack of thematerial at room temperature and also on the adhesion.

In the determination of the molar masses by means of gel permeationchromatography (GPC), the hydrodynamic radius of the polymer chainspresent in solution plays a particular role. As detection mechanisms,use is made of thermal conductivity detectors, RI (refractive index) orUV/VIS and FTIR or light-scattering detectors and also viscositydetectors. If the polymer chain is regarded as an undisturbed tangledball, the relationship between the limiting viscosity number and themolar mass can be described empirically by the KMHS equation[η]=K_(V)M_(V) ^(α)

(H.-G. Elias, Makromoleküle, volume 2, 6th edition, Wiley-VCH, Weinheim2001, pp. 411-413). K_(V) and α are constants which are influenced bothby the constitution, configuration and molar mass of the polymer and bythe solvent and the temperature. For the purposes of the presentinvention, the importance of the alpha value is that it indicates thehydrodynamic radius which depends more or less on the branching pointspresent on the polymer chains. At a low degree of branching, the alphavalue is high, while at a higher degree of branching it is low.

c) Rheology

The rheological measurements are carried out in accordance with ASTM D4440-01 (“Standard Test Method for Plastics: Dynamic MechanicalProperties Melt Rheology”) using an MCR 501 rheometer from Anton Paarhaving a plate-plate geometry (plate diameter: 50 mm) as oscillatorymeasurement. The maximum sample deformation used in all measurements is1%, and the temperature-dependent measurements are carried out at ameasurement frequency of 1 Hz and a cooling rate of 1.5 K/min.

The melt viscosity is determined by oscillatory rheometry at a shearrate of 1 Hz. The maximum deformation of the sample is selected so thatthe sample is in the linear viscoelastic range during the entiremeasurement time.

Viscoelastic materials differ from solids obeying Hooke's law in thatthey are capable of dissipating stresses resulting from deformation overa particular time (relaxation). In contrast to Newtonian liquids, whichundergo exclusively irreversible deformation under the action of shearstress/strain, viscoelastic fluids can recover part of the deformationenergy after the shear force has been removed (known as the “memoryeffect”) [N. P. Cheremisinoff; “An Introduction to Polymer Rheology andProcessing”; CRC Press; London; 1993]. A further characteristic ofpolymer melts is the occurrence of pseudoplasticity. This is behaviourin which the shear stress as applied force degrades the initialstructure of the material as a function of the shear rate. Since aminimum shear rate is required for this degradation process, thematerial flows like a Newtonian liquid below this shear rate. Anexplanation is given by Le Chatelier's principle, with the pseudoplasticliquid “getting out of the way” (of the mechanical stress) in thedirection along the shear surfaces serving to reduce the frictionalresistance. The latter leads to degradation of the equlibrium structureof the initial state and to the formation of a shear-oriented structure,which in turn results in easier flow (reduction of viscosity). Inpolymer melts, the Newtonian region is discernible only at very smallshear rates or small shear amplitudes. Its determination can be carriedout by rheometric test methods (amplitude sweeps, i.e. measurement at afixed frequency as a function of the shear amplitude) and is necessarywhen the measurement is to be carried out in the reversible, i.e.reproducible, range [R. S. Lenk; “Rheologie der Kunststoffe”; C. HanserVerlag; Munich; 1971; J. Meissner; “Rheologisches Verhalten vonKunststoff-Schmelzen und -Lösungen” in: “Praktische Rheologie derKunststoffe”; VDI-Verlag; Düsseldorf; 1978; J.-F. Jansson; Proc. 8th.Int. Congr. Rheol.; 1980; Vol. 3]. Vibrational rheometry is particularlywell suited to the examination of materials which display pseudoplasticbehaviour because of its low applied force, its low deformation and thusits small effect on the morphology of the sample.

d) Needle Penetration

The needle penetration is determined in accordance with DIN EN 1426.

e) DSC

The determination of the enthalpy of fusion, the glass transitiontemperature and the melting range of the crystalline proportion iscarried out by means of differential scanning calorimetry (DSC) inaccordance with DIN 53 765 from the second heating curve at a heatingrate of 10 K/min. The point of inflection of the heat flow curve istaken as the glass transition temperature.

f) Xylene Solubility

A xylene isomer mixture is used, and the polymer is dissolved underreflux and the solution is then cooled to room temperature.

2 g of polyolefin are dissolved in 250 mL of xylene with stirring andheating to the boiling point of xylene. After the mixture has beenrefluxed for 20 minutes, the polymer solution is allowed to cool to 25°C. Undissolved or precipitated polyolefin is filtered off with suction(15 cm suction filter, Sartorius 390 filter paper) and dried. Theremaining polymer solution is precipitated in a five-fold excess ofmethanol (admixed with one drop of 37% strength aqueous HCl). Theprecipitate formed is filtered off with suction and dried at 80° C. in adrying oven (vacuum).

g) Solubility in THF

Solubility in THF is a characteristic of partially crystallinepolyolefins. The determination is carried out by a method analogous tothe dissolution experiments in xylene.

h) Tensile Strength and Elongation at Break

The determination of the tensile strength and elongation at break iscarried out in accordance with DIN EN ISO 527-3.

i) Softening Point (Ring & Ball)

The determination of the softening point by the ring and ball method iscarried out in accordance with DIN EN 1427.

j) Adhesive Shear Strength

The determination of the adhesive shear strength is carried out inaccordance with DIN EN 1465.

Use of Metallocene Polyolefins Having Isotactic Structural Elements inFloor Coverings:

Examples

1. Polymers According to the Invention

a) Microstructure

The polymer composition and the microstructure of the polymers preparedare determined by high-temperature ¹³C-NMR.

Polymer 1 2 3 4 5 6 7 8 Polymer composition Ethylene [% by mass] 5 6 0 90 0 2 0 Propylene [% by mass] 92 83 20 82 83 100 0 90 1-Butene [% bymass] 3 11 80 9 17 0 98 10 Propylene triads Isotactic [% by mass] 82 8698 75 94 82 — 84 Syndiotactic [% by 4 4 0 6 2 7 — 6 mass] Atactic [1% bymass] 15 10 1 19 4 11 — 11 1-Butene triads Isotactic [% by mass] 20 4295 28 94 — 80 94 Atactic [% by mass] 80 49 3 63 6 — 16 4 Ethylene triads[% by 1.2 2.0 0 0.7 0 — 0 — mass] Polymer 9 10 11 12 13 14 15 Polymercomposition Ethylene [% by mass] 0 0 0 4 8 6 8.5 Propylene [% by mass] 085.5 6 96 85 88 80 1-Butene [% by mass] 100 14.5 94 0 7 6 11.5 Propylenetriads Isotactic [% by mass] — 86 99 75 76 79 75 Syndiotactic [% by — 4— 6 6 6 6 mass] Atactic [% by mass] — 10 1 19 18 16 19 1-Butene triadsIsotactic [% by mass] 94 90 98 — 26 22 34 Atactic [% by mass] 5 10 1 —70 70 57 Ethylene triads [% by — — — 0 1.3 0.8 1.9 mass]

b) Molar Masses, Molar Mass Distribution and Polymer Branching

The determination of the molecular weight is carried out byhigh-temperature GPC. The determination is carried out as described inASTM D6474-99 but at a higher temperature (160° C. instead of 140° C.)and using a smaller injection volume of 150 μl instead of 300 μl.Examples of molar mass distributions according to the invention and notaccording to the invention with and without a low molecular weightfraction are shown in the drawings.

Polymer 1 2 3 4 5 Modality MMV bimodal bimodal bimodal monomodalmonomodal M_(w) [g/mol] 33200 27600 56000 83000 76700 Pd [—] 2.1 2.8 2.41.5 1.5 α value [—] 0.67 0.58 0.76 1.04 1.01 Constituents 0 0.5 0 0 01000-500 D Constituents < 0 0 0 0 0 500 D Polymer 6 7 8 9 10 ModalityMMV monomodal monomodal monomodal bimodal monomodal M_(w) [g/mol] 1930016000 15200 20200 15100 Pd [—] 1.5 1.5 1.7 1.5 1.7 α value [—] 0.86 0.810.72 0.79 0.74 Constituents 0 0 0 0 0 1000-500 D Constituents < 0 0 0 00 500 D Polymer 11 12 13 14 15 Modality MMV monomodal bimodal monomodalmonomodal bimodal M_(w) [g/mol] 15900 15000 44700 50700 38000 Pd [—] 1.71.6 1.4 1.5 1.6 α value [—] 0.73 0.82 0.85 0.93 0.88 Constituents 0 0 00 0 1000-500 D Constituents < 0 0 0 0 0 500 D

c) Thermal Properties:

The determination of the softening point by the ring and ball method iscarried out in accordance with DIN EN 1427.

The determination of the enthalpy of fusion, the glass transitiontemperature and the melting range of the crystalline fraction is carriedout by differential scanning calorimetry (DSC) in accordance with DIN 53765 from the second heating curve at a heating rate of 10 K/min. Thepoint of inflection of the heat flow curve is taken as the glasstransition temperature. An illustrative DSC thermogram for a polyolefinaccording to the invention may be found in the drawings.

Polymer 1 2 3 4 5 Softening point (R&B) 130 118 80 97 116 [° C.] Numberof melting peaks 2 2 2 1 2 in first heating First heating T_(M) [° C.]120 108 75 111 47 129 116 92 108 Number of melting peaks 2 2 1 1 1 insecond heating Second heating T_(M) [° C.] 120 110 95 96 110 127 120Second heating: ΔH_(M) [J/g] 30.6 35.1 10.3 10.1 54 Second heating:T_(g) [° C.] −18 −43 −32 −35 −20 Cold crystallization No No No No No(peak at: [° C.]) (—) (—) (—) (—) (—) Second heating: T_(M) offset 140128 100 125 118 [° C.] Δ [T_(M) − T_(soft)] [K] 3 2 14 1 6 Polymer 6 7 89 10 Softening point (R&B) [° C.] 138 87 107 113 99 Number of meltingpeaks 2 3 1 2 1 in first heating First heating T_(M) [° C.] 126 39 10151 93 134 60 111 81 Number of melting peaks 1 1 1 2 1 in second heatingSecond heating T_(M) [° C.] 129 80 99.5 76 92 87 Second heating: ΔH_(M)[J/g] 51 33 46.2 26.4 46 Second heating: T_(g) [° C.] −9.5 −40 −19 −38*−20 Second heating, cold No Yes No No No crystallization (—) (+12) (—)(—) (—) (peak at: [° C.]) Second heating: T_(M) offset 140 90 111 96 105[° C.] Δ [T_(M) − T_(soft)] [K] 11 8 7.5 26 7 Polymer 11 12 13 14 15Softening point (R&B) [° C.] 105 117 121 132 119 Number of melting peaks2 3 2 2 3 in first heating First heating T_(M) [° C.] 75 53 102 122 8098 95 120 132 111 120 120 Number of melting peaks 3 2 2 2 3 in secondheating Second heating T_(M) [° C.] 68 108 105 122 88 81 120 120 130 0691 113 Second heating: ΔH_(M) [J/g] 41.9 36.4 14.9 28 26.1 Secondheating: T_(g) [° C.] −38 −26 −40 −21 −34 Second heating, cold Yes No NoNo No crystallization (−9 & (—) (—) (—) (—) (peak at: [° C.]) +12)Second heating: T_(M) offset 102 126 131 135 125 [° C.] Δ [T_(M) −T_(soft)] [K] 14 3 1 2 6 *Glass transition step only weakly defined

d) Adhesive Properties

The determination of the adhesive shear strength is carried out inaccordance with DIN EN 1465. The polymer samples are melted for one hourat 190° C. in a drying oven under a protective gas atmosphere (e.g.nitrogen, argon, etc.) and subsequently applied to a test specimen at atemperature of 170° C. (by means of a temperature sensor). The testspecimen is brought into contact with a further test specimen of thesame material, within 20 seconds, with a simple overlap over an area of4 cm² and pressed together for 5 minutes by means of a weight of 2 kg.Protruding adhesive polymer is removed. The adhesively bonded specimenis subsequently stored for 7 days at 20° C./65% relative atmospherichumidity in a temperature- and humidity-controlled cabinet and itsmechanical properties are subsequently tested by means of a tensiletest. Test materials used are untreated beech wood (thickness: 2 mm),untreated isotactic polypropylene (thickness: 2 mm, isotacticpolypropylene, “PP-DWST”/manufacturer: Simona AG), untreatedpolyethylene (thickness: 2 mm; “PE-HWST” manufacturer: Simona AG) anduntreated poly(vinyl chloride) (thickness: 2 mm, unplasticized PVC“Kommadur ES”; manufacturer: Kömmerling-Profine)).

Polymer 1 2 3 4 5 6 Needle penetration 2 2 4 11 2 2 [0.1 mm] Meltviscosity at 190° C. 2500 1200 9700 17000 5400 1100 [mPa * s] Adhesiveshear strength 1.45 1 1.1 2 1.45 0.55 PP/PP [MPa] Adhesive shearstrength 2.35 2.25 3.3 1.9 2.9 2.9 beech/beech [MPa] Adhesive shearstrength 0.05 0.15 0.2 0.36 0.2 n.d. PE/PE [MPa] Adhesive shear strength0.35 0.3 0.35 0.6 0.3 n.d. PVC/PVC [MPa] Tensile strength [MPa] 7.1 5.818 2.3 15.2 12.3 Elongation at break [%] 20 10 430 430 10 10 Xylenesolubility [% by 48 85 100 100 38 100 mass] THF solubility [% by 16 28.599.5 100 2 99.5 mass] Polymer 7 8 9 10 11 12 Needle penetration 7 1 2 11 6 [0.1 mm] Melt viscosity at 190° C. 630 600 620 600 680 630 [mPa * s]Adhesive shear strength 0.4 0.35 0.3 0.35 0.25 0.6 PP/PP [MPa] Adhesiveshear strength 1.1 0.75 1.3 0.85 1.65 1.70 beech/beech [MPa] Adhesiveshear strength 0.15 0.1 0.07 0.12 0.08 0.15 PE/PE [MPa] Adhesive shearstrength 0.21 0.2 0.12 0.18 0.17 n.d. PVC/PVC [MPa] Tensile strength[MPa] 1.1 1.2 1.5 1.3 1.75 2.1 Elongation at break [%] 10 10 15 10 20 10Xylene solubility [% by 99 96.6 99.4 99.0 97.9 84.9 mass] THF solubility[% by 99.4 97.5 10.4 98.6 32.7 70.2 mass] Polymer 13 14 15 Needlepenetration [0.1 mm] 6 4 7 Melt viscosity at 190° C. 21000 29000 8000[mPa * s] Adhesive shear strength 3 1.6 2.5 PP/PP [MPa] Adhesive shearstrength 3 4.85 2.5 beech/beech [MPa] Adhesive shear strength 0.3 0.170.3 PE/PE [MPa] Adhesive shear strength 0.5 0.8 0.3 PVC/PVC [MPa]Tensile strength [MPa] 6.5 8.1 4 Elongation at break [%] 800 75 40Xylene solubility [% by mass] 99.3 59.6 91 THF solubility [% by mass] 9225.4 74

e) Rheological Properties

Examples of the frequency dependence of complex viscosity, storagemodulus and loss modulus of a polyolefin according to the invention maybe found in the drawings.

Illustrated Formulations for Nap and Filament Binding of Raw Carpet forTesting of Pile Binding of Hot Melt Coatings Based on PolyolefinFormulations According to the Invention for Tufted Carpets

Procedure:

After melting of the polymers according to the invention at 190° C. in adrying oven under protective gas atmosphere (e.g. nitrogen, argon, etc.)for one hour, the formulation constituents are added, melted ifappropriate and the mixture is then mixed until homogeneous by means ofa suitable mixing apparatus (e.g. on a hotplate using an IKA stirrerwith kneader). The materials properties of the formulations aredetermined, and the raw carpet is subsequently coated by multirollerapplication and application by means of a slit die and doctor blade.

Experiment No. A B C D E Polymer 1 according to the % by 55 60 45 50 40invention weight (viscosity at 190° C.: 2500 mPa * s Penetration: 20.1mm, EP: 130° C.) VESTOPLAST ® 750, from Evonik % by 5 5 5 Degussa GmbHweight ESCOREZ 5300, from ExxonMobil % by 35 35 40 40 40 Chemical weightVESTOWAX ® A415, from Evonik % by 10 5 10 5 5 Degussa GmbH weightMikrosöhl (chalk) % by 10 weight Softening point (R&B) ° C. 133 128 122129 131 Needle penetration 0.1 mm 4 2 5 7 3 Melt viscosity at 190° C.mPa * s 2100 2340 2430 2510 3100

Testing of Pile Binding of Hot Melt Coatings Based on PolyolefinFormulations According to the Invention for Tufted Carpets in Threedifferent Application Forms

Precoating on a polyamide tufting carpet backing 620 g/m² Multirollerapplication Experiment No. A B C D E Coating weight g/m² 250 270 290 300310 Nap tear-out resistance kg 6.1 6.3 6.1 5.7 6.2 Testing using thetread wheel apparatus by a method based on the Lisson system EN 1963Visual assement after  750 ++ ++ ++ ++ ++ number of tread frequencies1000 ++ ++ ++ ++ ++ 1500 ++ ++ ++ ++ ++ 2300 ++ ++ +/++ ++ ++

Application using a slit die Experiment No. A B C D E Coating weightg/m² 400 430 400 390 390 Nap tear-out resistance kg 6.1 5.6 6.3 6.3 6.2Testing using the tread wheel apparatus by a method based on the Lissonsystem EN 1963 Visual assement after  750 ++ ++ ++ ++ ++ number of treadfrequencies 1000 ++ ++ ++ ++ ++ 1500 ++ +/++ ++ ++ ++ 2300 +/++ +/++ ++++ ++

Application using a doctor blade Experiment No. A B C D E Coating weightg/m² 390 410 400 360 360 Nap tear-out resistance kg 5.9 5.7 5.8 6.2 6.2Testing using the tread wheel apparatus by a method based on the Lissonsystem EN 1963 Visual assement after  750 ++ ++ ++ ++ ++ number of treadfrequencies 1000 ++ ++ ++ ++ ++ 1500 ++ +/++ +/++ ++ ++ 2300 ++ +/+++/++ ++ ++ ◯ moderate + good ++ very good

The invention claimed is:
 1. A polyolefin for floor coverings, whereinthe polyolefin is a copolymer of ethylene, propylene and 1-butenecomprising ethylene and propylene in a total amount of not more than 20%by mass and 80-98% by mass of 1-butene, with the sum of the proportionsbeing 100% by mass, wherein the triad distribution for 1-butene triadsdetermined by ¹³C-NMR has an isotactic proportion of 10-98% by mass, anatactic proportion of 1-85% by mass and a syndiotactic proportion of notmore than 20% by mass, wherein the polyolefin has at least one meltingpeak in the DSC at a temperature in the range of 30-95° C. and whereinthe isotactic proportion of the propene triads is 75-82%.
 2. Thepolyolefin according to claim 1, wherein the floor coverings are carpetsor artificial lawns.
 3. An adhesive comprising the polyolefin accordingto claim
 1. 4. The adhesive according to claim 3, in the form of a hotmelt adhesive formulation.
 5. A heavy coating composition comprising thepolyolefin according to claim
 1. 6. The adhesive according to claim 3,wherein the adhesives additionally contain inorganic and/or organicfillers, inorganic and/or organic pigments, synthetic and/or naturalresins, inorganic and/or organic, synthetic and/or natural polymers,inorganic and/or organic, synthetic and/or natural fibres, inorganicand/or organic stabilizers, inorganic and/or organic flame retardants,resins, amorphous poly(α-olefins), polymers having polar groups,polymers based on ethylene, butadiene, styrene and/or isoprene,elastomeric polymers based on ethylene, propylene, acrylonitrile, adiene and/or a cyclic diene, styrene, waxes, one or more synthetic ornatural oils and/or UV-active substances.
 7. A polyolefin compositioncomprising the polyolefin according to claim 1, wherein the polyolefincomposition is in the form of at least one of a nap binder, a filamentbinder and a rear-side coating.
 8. A floor covering comprising thepolyolefin according to claim 1 in an amount of from 20 to 1500 g/m². 9.The polyolefin according to claim 1, wherein the floor coverings arebased on natural and/or synthetic fibres.
 10. The polyolefin accordingto claim 1, wherein the needle penetration of the polyolefin is not morethan 35*0.1 mm.
 11. The polyolefin according to claim 1, wherein thepolyolefin has a complex melt viscosity at a temperature of 190° C., adeformation of not more than 1% and a measurement frequency of 1 Hz offrom 600 to 400000 mPa*s.
 12. The polyolefin according to claim 1,wherein the glass transition temperature of the polyolefin determined bymeans of DSC is not more than −5° C.
 13. A polyolefin hot melt adhesivefor nap and/or filament binding, wherein the polyolefin is a copolymerof ethylene, propylene and 1-butene comprising ethylene and propylene ina total amount of not more than 20% by mass and 80-98% by mass of1-butene, with the sum of the proportions being 100% by mass, andwherein the triad distribution for 1-butene triads determined by ¹³C-NMRhas an isotactic proportion of 10-98% by mass, an atactic proportion of1-85% by mass and a syndiotactic proportion of not more than 20% bymass, wherein the polyolefin has at least one melting peak in the DSC ata temperature in the range of 30-95° C. and wherein the isotacticproportion of the propene triads is 75-82%.
 14. A polyolefin heavycoating composition for the production of floor coverings, wherein thepolyolefin is a copolymer of ethylene, propylene and 1-butene comprisingethylene and propylene in a total amount of not more than 20% by mass of1-butene and 80-98% by mass, with the sum of the proportions being 100%by mass, and wherein the triad distribution for 1-butene triadsdetermined by ¹³C-NMR has an isotactic proportion of 10-98% by mass, anatactic proportion of 1-85% by mass and a syndiotactic proportion of notmore than 20% by mass, wherein the polyolefin has at least one meltingpeak in the DSC at a temperature in the range of 30-95° C. and whereinthe isotactic proportion of the propene triads is 75-82%.
 15. A floorcovering comprising a polyolefin, wherein the polyolefin is a copolymerof ethylene, propylene and 1-butene comprising ethylene and propylene ina total amount of not more than 20% by mass and 80-98% by mass of1-butene the sum of the proportions being 100% by mass, and wherein thetriad distribution for 1-butene triads determined by ¹³C-NMR has anisotactic proportion of 10-98% by mass, an atactic proportion of 1-85%by mass and a syndiotactic proportion of not more than 20% by mass,wherein the polyolefin has at least one melting peak in the DSC at atemperature in the range of 30-95° C. and wherein the isotacticproportion of the propene triads is 75-82%.
 16. The floor coveringaccording to claim 15, wherein said floor covering is a carpet orartificial lawn.
 17. The heavy coating composition according to claim 5,wherein the heavy coating compositions additionally contain inorganicand/or organic fillers, inorganic and/or organic pigments, syntheticand/or natural resins, inorganic and/or organic, synthetic and/ornatural polymers, inorganic and/or organic, synthetic and/or naturalfibres, inorganic and/or organic stabilizers, inorganic and/or organicflame retardants, resins, amorphous poly(α-olefins), polymers havingpolar groups, polymers based on ethylene, butadiene, styrene and/orisoprene, elastomeric polymers based on ethylene, propylene,acrylonitrile, a diene and/or a cyclic diene, styrene, waxes, one ormore synthetic or natural oils and/or UV-active substances.